Preterm Premature Rupture of the Membranes

🏷

Classifications

Harrison's Part

🔗

Mappings

ICD-10-CM

ICD10CM:O42.919 Preterm premature rupture of membranes, unspecified as to length of time between rupture and onset of labor, unspecified trimester

The single ICD-10-CM code that names preterm premature rupture of the membranes with both of its qualifying axes left unspecified, which is the nearest coded equivalent of this entry's disease unit. closeMatch rather than exactMatch because the code remains a member of a latency-stratified family: ICD-10-CM cuts PPROM along two axes this entry does not use - the interval between rupture and the onset of labour, and the trimester - giving nine preterm codes (O42.011-O42.019, O42.111-O42.119, O42.911-O42.919). Mapping all nine would assert nine disease units where this entry curates one, so a claims query should expand to that family rather than read this mapping as exhaustive.

ICD10CM:O42 Premature rupture of membranes

The ICD-10-CM category covering rupture of the membranes before labour at any gestation. It is broader than this entry, which is restricted to rupture before 37 weeks: O42.02, O42.12 and O42.92 code the full-term case, which this entry treats as a differential diagnosis rather than as itself.

◆

Subtypes

3

Previable PPROM (rupture before about 23 weeks)

Rupture before the threshold of viability. It is separated from the others because the dominant pathology is not prematurity but the consequence of prolonged anhydramnios during the canalicular phase of lung development: pulmonary hypoplasia and skeletal deformation, on top of a high rate of intrauterine loss. The counselling and the management decision are categorically different from later PPROM, which is why this is a subtype rather than a severity grade.

Show evidence (1 reference)

PMID:8828433 SUPPORT Human Clinical

"Severe oligohydramnios > 14 days after premature rupture of membranes at < 25 weeks' gestation has a predicted neonatal mortality of > 90%."

Quantifies the outcome that distinguishes this subtype - mortality driven by duration of severe oligohydramnios and gestational age at rupture, not by the rupture itself.

Early-preterm PPROM (about 23 to 33 weeks)

The gestational window in which latency antibiotics, antenatal corticosteroids and magnesium sulphate are all indicated and in which prolonging the pregnancy is worth the infection risk. The randomised evidence that defines expectant management with antibiotics was generated in this window.

Show evidence (1 reference)

PMID:9307346 SUPPORT Human Clinical

"A total of 614 of 804 eligible gravidas with PPROM between 24 weeks' and 0 days' and 32 weeks' and 0 days' gestation who were considered candidates for pregnancy prolongation"

Defines the gestational window of the trial that established latency antibiotics, which is the window this subtype names.

Late-preterm PPROM (34 to 36 weeks and 6 days)

Rupture close to term, where the balance flips: the fetus is mature enough that the infection risk of waiting was long assumed to outweigh the prematurity risk of delivering. The PPROMT trial tested exactly that assumption in this window and found against it, which is why the window is worth separating.

Show evidence (1 reference)

PMID:26564381 SUPPORT Human Clinical

"Women aged over 16 years with singleton pregnancies and ruptured membranes before the onset of labour between 34 weeks and 36 weeks and 6 days weeks who had no signs of infection were included."

States the gestational bounds that define this subtype, as used by the trial that governs its management.

?

Discussions and Knowledge Gaps

3

Is premature senescence of the amniochorion a cause of PPROM, or a marker of membranes that were already destined to fail?

KNOWLEDGE GAP OPEN gap_pprom_senescence_cause_or_marker

Attached to

pathophysiology#Premature Senescence of the Amniochorion

The senescence evidence is strong on association and on inducibility, and those are different claims. Membranes from PPROM carry the markers at term-like frequencies, and an oxidant exposure produces the same phenotype in term membranes in vitro - but no study shows that blocking senescence prevents rupture, and no in vivo experiment separates senescence from the oxidative stress that induces it. The distinction is not academic: it decides whether senescence is a screening biomarker or a therapeutic target, and the field's own reviews call for exactly this work.

Proposed experiments

Senescence blockade in a fetal membrane organ-on-chip under oxidant challenge

exp_pprom_senescence_blockade_mechanical_endpoint

Apply an oxidant challenge to a human fetal membrane organ-on-chip with and without senolytic or p38 inhibition, and measure both the senescence markers and a mechanical endpoint. The mechanical endpoint is the point of the experiment: showing that blockade prevents marker accumulation would only repeat what is already known.

Would support

pathophysiology#Premature Senescence of the Amniochorion

Supporting outcome

Senescence blockade preserves membrane tensile strength or rupture pressure under an oxidant challenge that weakens untreated membranes.

Refuting outcome

Senescence markers are suppressed but the membranes weaken to the same degree, placing the mechanical failure downstream of oxidative stress but not of senescence.

Show evidence (1 reference)

PMID:28807394 SUPPORT REVIEW SYNTHESIS Other

"Further studies on senescence activation and microfracture formation and their role in maintaining membrane homeostasis are needed to fill the knowledge gaps in our understanding of pPROM"

The review states this gap in its own words, which is why it is recorded here rather than inferred. OTHER is correct and stays: a statement that evidence is missing describes no study. REVIEW_SYNTHESIS marks it as the review's assessment.

Does an organism recovered from the amniotic cavity after PPROM reflect a cause of the rupture or a consequence of it?

KNOWLEDGE GAP OPEN gap_pprom_organism_direction

Attached to

pathophysiology#Ascending Choriodecidual Microbial Colonization pathophysiology#Ascending Intraamniotic Infection After Rupture

This entry deliberately splits colonisation before rupture from infection after it, because the literature very largely cannot. Amniotic fluid is sampled after the membranes have opened, at which point the cavity is continuous with the vagina, so a positive culture is compatible with either direction. The consequence is practical: the fraction of PPROM that is genuinely infection-initiated is not established, and the observation that much intraamniotic inflammation is culture-negative is consistent with either a sterile mechanism or an unrecovered organism.

Proposed experiments

Pre-rupture longitudinal sampling in a high-risk cohort

exp_pprom_pre_rupture_sampling

Serial cervicovaginal and, where amniocentesis is independently indicated, amniotic sampling with molecular microbiology in a cohort at high risk of PPROM, so that organism presence is established before the barrier fails rather than after.

Would support

pathophysiology#Ascending Choriodecidual Microbial Colonization

Supporting outcome

Organisms detectable in the amniotic cavity before rupture in a substantial fraction of women who subsequently rupture, at rates exceeding matched women who do not.

Refuting outcome

Pre-rupture sampling is sterile in most women who go on to rupture, placing the recovered organisms after the event and reducing the infectious route to a minority mechanism.

Show evidence (1 reference)

PMID:32591087 SUPPORT Human Clinical

"sterile intraamniotic inflammation was defined as the presence of intraamniotic inflammation without microbial invasion of the amniotic cavity"

The existence of a named, operationalised sterile category is what makes the direction question answerable rather than rhetorical.

Why is there no MONDO term for preterm birth itself, when PPROM - one of its causes - has one?

KNOWLEDGE GAP OPEN gap_pprom_no_mondo_term_for_preterm_birth

Attached to

disease#Preterm Premature Rupture of the Membranes

Searching MONDO for preterm birth, premature birth, preterm labor and obstetric labor complication returns no general term for the condition; the only anchorable obstetric concept in this area is preterm premature rupture of the membranes (MONDO:0012511), which is why this entry exists in this shape. Preterm birth is available in HPO as a phenotype (HP:0001622 Premature birth, with the WHO severity strata HP:0025664, HP:0025665 and HP:0025666), so the gap is specifically a disease anchor. This is the same class of blocker that issue 7837 records for postpartum haemorrhage. It is recorded here as a gap rather than worked around, and it is worth a MONDO new-term request.

Note also that MONDO classifies MONDO:0012511 under hereditary disease - it is reachable from MONDO:0003847 - which fits the SERPINH1 susceptibility literature the OMIM entry rests on but not the multifactorial entity this file curates. Worth raising upstream alongside the missing preterm-birth term.

⚙

Pathophysiology

13

Oxidative Stress in the Fetal Membranes

Reactive oxygen species accumulate in the amniochorion during gestation and are accelerated by risk-factor exposures. This is the node the contemporary model puts upstream of everything else in the non-infectious route to PPROM, and it is also the node at which the main modifiable risk factor - smoking - acts.

epithelial cell of amnion CL:0002536 amnion mesenchymal fibroblast CL:0000057

response to oxidative stress GO:0006979 ↑ INCREASED

amnion UBERON:0000305 chorion membrane UBERON:0003124

Downstream

Premature Senescence of the Amniochorion The strongest experimental support is that the senescence phenotype can be induced in term membranes in vitro by an oxidant exposure, which makes this an inducible relationship rather than only a correlated one.

Show evidence (1 reference)

PMID:32785751 SUPPORT REVIEW SYNTHESIS In Vitro

"The intrauterine build-up of oxidative stress at term or in response to risk factors (preterm) can accelerate senescence and promote a terminal state of EMT, resulting in the accumulation of inflammation."

States the oxidative-stress-to-senescence-to-inflammation sequence that the next two nodes model, and marks the preterm case as risk-factor driven. The acceleration claim rests on oxidant exposure of cultured fetal membrane cells and organ explants - the same experimental route as PMID:24832021 on the edge below - so it is graded IN_VITRO, with REVIEW_SYNTHESIS recording that this review did not perform those experiments.

Premature Senescence of the Amniochorion

Fetal membrane cells in PPROM carry the senescence markers p53, p21 and phospho-p38 MAPK at frequencies resembling term membranes rather than gestational-age-matched preterm ones - the membranes have aged early. Fetal telomere length points the same way. The clinical reading is that PPROM membranes have reached, prematurely, the state that normally permits rupture at term.

epithelial cell of amnion CL:0002536

cellular senescence GO:0090398 ↑ INCREASED

amnion UBERON:0000305

Downstream

Microfracture Formation in the Amnion Microfractures appear as extensions of areas the amnion has vacated through shedding or senescence-associated topographic change. The cited source postulates the link rather than demonstrating it, and says so.

Intraamniotic Inflammatory Response The senescence-associated secretory phenotype is the proposed source of the sterile intraamniotic inflammation seen in PPROM without microbial invasion. This is the edge that makes a single model cover both the infected and the culture-negative cases.

Show evidence (2 references)

PMID:24832021 SUPPORT Human Clinical

"A total of 80% of pPROM cells and >60% of term cells were positive for all three senescence phenotype markers, and concentrations were higher than in PTBs (P < 0.05)."

The comparator is the informative part: PPROM membranes resemble term membranes and differ from gestational-age-matched spontaneous preterm birth, which is what makes this specific to PPROM rather than to prematurity.

PMID:22348044 SUPPORT INDIRECT Human Clinical

"pPROM had telomere lengths (9962 ± 3124 bp) that were significantly shorter than gestational age-matched PTB (11546 ± 4348 bp, p = 0.04), but comparable to term births (9011 ± 2497 bp, p = 0.31)."

A second, independent marker of the same early-ageing pattern. INDIRECT because telomere length is a surrogate for oxidative stress and senescence rather than a measurement of the membrane state itself, and because it was measured in cord blood leukocytes - the study reports a strong correlation with placental membrane telomere length, which is the step that licenses the inference.

Ascending Choriodecidual Microbial Colonization

Organisms ascend from the lower genital tract into the choriodecidual space and, in a subset, into the amniotic cavity. This is the classic route and it remains the one the treatment is aimed at, but it is not the only route: a substantial fraction of PPROM has intraamniotic inflammation with no recoverable organism, which is why the inflammation node below is kept separate from this one.

decidual cell CL:2000002 neutrophil CL:0000775

decidua UBERON:0002450 amniotic fluid UBERON:0000173

Downstream

Intraamniotic Inflammatory Response

Show evidence (1 reference)

PMID:9307346 SUPPORT BACKGROUND Human Clinical

"Intrauterine infection is thought to be one cause of preterm premature rupture of the membranes (PPROM)."

Records the hypothesis at the strength its own source states it - thought to be one cause. Tagged BACKGROUND because it is the trial's framing sentence, not its result; the trial's result is cited on the antibiotic treatment. The sentence summarises human clinical observation, so HUMAN_CLINICAL + BACKGROUND is the pair that is true of it - OTHER would have asserted nothing about the evidence.

Intraamniotic Inflammatory Response

Raised amniotic fluid interleukin-6 with or without recoverable organisms. The distinction is operationalised in the literature and matters here: intraamniotic infection is microbial invasion plus inflammation, whereas sterile intraamniotic inflammation is inflammation without invasion. Both drive the same downstream proteolysis, which is why this entry models the inflammation rather than the infection as the pathogenic node.

neutrophil CL:0000775 macrophage CL:0000235

inflammatory response GO:0006954 ↑ INCREASED cytokine-mediated signaling pathway GO:0019221 ↑ INCREASED

amniotic fluid UBERON:0000173

Downstream

Matrix Metalloproteinase-Mediated Collagen Degradation in the Amniochorion

Onset of Preterm Parturition Intraamniotic inflammation activates the myometrium as well as degrading the membranes, so an inflamed pregnancy can reach preterm delivery without waiting for the barrier failure. This is the edge that makes latency finite even when the rupture is managed perfectly.

Show evidence (2 references)

PMID:32591087 SUPPORT Human Clinical

"Intraamniotic infection was defined as the presence of both microbial invasion of the amniotic cavity and intraamniotic inflammation; sterile intraamniotic inflammation was defined as the presence of intraamniotic inflammation without microbial invasion of the amniotic cavity."

The operational definitions that separate the infected from the sterile route, both of which this node covers.

PMID:32785751 SUPPORT REVIEW SYNTHESIS In Vitro

"Inflammation degrades the matrix and destabilizes membrane function."

States the inflammation-to-matrix step that the downstream edge asserts. The degradation and mechanical-destabilisation work behind the sentence is done on cultured fetal membrane explants, so it is graded IN_VITRO rather than OTHER, and REVIEW_SYNTHESIS records that the citing publication is a review.

Decidual Haemorrhage and Thrombin Generation

Bleeding at the decidual interface generates thrombin, which overrides the progestin suppression of collagenase expression in decidual cells. This is a maternal-side entry into the same proteolytic node and is the mechanistic account of why placental abruption and PPROM travel together clinically.

decidual cell CL:2000002

decidua UBERON:0002450

Downstream

Matrix Metalloproteinase-Mediated Collagen Degradation in the Amniochorion

Show evidence (1 reference)

PMID:12380602 SUPPORT INDIRECT In Vitro

"MPA strongly inhibited MMP-1 levels in endometrial stromal and term decidual cells. However, thrombin overcame this suppression, producing MMP-1 levels that were several-fold higher than control levels."

The measured result: thrombin defeats the progestin brake on interstitial collagenase. INDIRECT because it is cultured cells under a hormonal mimic, and the authors themselves describe the step to the pregnant state as an extrapolation.

Reduced Amnion Collagen Synthesis

Amnion fibroblasts lay down the fibrillar collagen that gives the sheet its tensile strength, and that synthesis depends on the collagen-specific chaperone HSP47, encoded by SERPINH1. A promoter allele that lowers SERPINH1 transcription is the one genetic finding in PPROM that has both an effect on the molecule and a replicated clinical association, so this node is the genetic entry point into the same structural failure the proteolytic nodes reach from the other direction.

amnion mesenchymal fibroblast CL:0000057

SERPINH1 hgnc:1546

collagen biosynthetic process GO:0032964 ↓ DECREASED protein folding GO:0006457 ↓ DECREASED

amnion UBERON:0000305

Downstream

Loss of Amniochorion Tensile Strength Reduced chaperone availability to reduced tensile strength is the plausible and intended reading of the genetic finding, but no study measures membrane tensile strength as a function of SERPINH1 genotype. The edge is recorded at that strength.

Show evidence (1 reference)

PMID:16938879 SUPPORT Human Clinical

"The -656 T allele displayed significantly reduced promoter activity compared to the major -656 C allele in amnion fibroblasts, which lay down the fibrillar collagen that gives tensile strength to the amnion."

Gives both halves of this node in one sentence: the molecular effect of the allele and the reason amnion fibroblast collagen is the load-bearing element.

Matrix Metalloproteinase-Mediated Collagen Degradation in the Amniochorion

MMP-9 (gelatinase B) rises in amniotic fluid around membrane rupture, and MMP-1 (interstitial collagenase) is the thrombin-inducible arm. The relevant quantity is protease activity against the tissue inhibitors of metalloproteinases rather than either alone. This is the convergence node: the infectious, sterile-inflammatory and haemorrhagic routes all arrive here.

MMP9 hgnc:7176 MMP1 hgnc:7155 TIMP1 hgnc:11820

collagen catabolic process GO:0030574 ↑ INCREASED extracellular matrix disassembly GO:0022617 ↑ INCREASED

amnion UBERON:0000305 chorion membrane UBERON:0003124

Downstream

Loss of Amniochorion Tensile Strength

Show evidence (2 references)

PMID:9822510 SUPPORT Human Clinical

"Our data support a role for matrix metalloproteinase-9 in the mechanisms responsible for membrane rupture in term and preterm gestations."

The authors' own conclusion from amniotic fluid measurements across 201 women in six clinically defined groups.

PMID:9822510 SUPPORT BACKGROUND In Vitro

"Matrix metalloproteinases are enzymes capable of degrading extracellular matrix macromolecules, including collagens."

The substrate rationale for the node. Tagged BACKGROUND because it is the paper's framing of established biochemistry rather than its own measurement. What the sentence describes is enzyme activity on matrix substrates - a biochemical assay outside an organism - so IN_VITRO is what it is evidence of, even though the citing paper is a human cross-sectional study.

Microfracture Formation in the Amnion

Microfractures are channels or tunnels through the amnion, visible by nonlinear microscopy, that appear where amnion cells have been shed or the surface has been altered by senescence. They are present in normal membranes too and are read as sites of ordinary remodelling; what distinguishes PPROM is that there are more of them and they are wider and deeper, which is interpreted as remodelling that failed. They matter twice over, as a structural defect and as a conduit.

amnion UBERON:0000305

Downstream

Loss of Amniochorion Tensile Strength The source postulates that microfractures mark insufficient or ineffective remodelling rather than demonstrating that they cause the sheet to fail, and the edge is recorded at that strength.

Show evidence (2 references)

PMID:28807394 SUPPORT Human Clinical

"The number of microfractures and their dimensions (wider and deeper) are significantly higher in fetal membranes from pPROM than gestational age matched sPTB tissues."

The comparison that makes microfractures specific to PPROM rather than to preterm delivery in general.

PMID:28807394 SUPPORT REVIEW SYNTHESIS Human Clinical

"Microfractures can act as channels for amniotic fluid leak, and inflammatory cell and microbial migration."

The conduit reading, which is the proposed route by which a structural defect becomes both a leak and an infection pathway before frank rupture. Graded to match the measurement item above it: the same imaging of human PPROM membranes, read functionally. REVIEW_SYNTHESIS marks it as the review's interpretation, which is also why the edge below it is recorded as INDIRECT_UNKNOWN_INTERMEDIATES.

Loss of Amniochorion Tensile Strength

The mechanical endpoint of every upstream branch: the amniochorion can no longer carry the load it is subjected to. Keeping this node separate from rupture itself is deliberate - it is the state a membrane can be in for days or weeks before it gives way, and it is the state a biomarker or imaging test would have to detect to be useful before the event.

collagen fibril organization GO:0030199 ↓ DECREASED

amnion UBERON:0000305 chorion membrane UBERON:0003124

Downstream

Rupture of the Chorioamniotic Membranes Before 37 Weeks

Show evidence (1 reference)

PMID:28807394 SUPPORT REVIEW SYNTHESIS Other

"we introduce the concept that pPROM is a disease of the fetal membranes where inflammation-oxidative stress axis plays a major role in producing pathways that can lead to membrane weakening through a variety of processes"

The framing claim this node encodes - that the several upstream pathways converge on membrane weakening - stated by the review that proposes it. OTHER is retained deliberately here: the sentence introduces a conceptual model and describes no study, so there is no evidence type to grade, and REVIEW_SYNTHESIS now carries the fact that this is the review's own synthesis.

Rupture of the Chorioamniotic Membranes Before 37 Weeks

The defining lesion, and the point at which the disease changes character. Up to here the pathology is a progressive weakening of one tissue; from here it is a breached barrier, and what follows is driven by what the breach allows rather than by what caused it.

amnion UBERON:0000305 chorion membrane UBERON:0003124

Downstream

Preterm premature rupture of membranes The clinically observed presentation of this node.

Loss of the Amniotic Fluid Barrier

Onset of Preterm Parturition

Loss of the Amniotic Fluid Barrier

Amniotic fluid drains and the amniotic cavity is continuous with the vagina. Two separate harms follow and they scale with different things: fluid volume loss harms the fetus in proportion to how early it happens and how long it lasts, whereas the open conduit harms in proportion to latency alone.

amniotic fluid UBERON:0000173 uterine cervix UBERON:0000002

Downstream

Oligohydramnios

Ascending Intraamniotic Infection After Rupture

Colonisation of the now-open amniotic cavity. This is a separate node from the ascending colonisation that may have caused the rupture, and confusing the two is the standard trap in reading the PPROM literature: an organism recovered after rupture may have arrived because of it. The node is retained because it is what latency antibiotics are given against and what limits how long expectant management can run.

neutrophil CL:0000775

leukocyte migration GO:0050900 ↑ INCREASED

amniotic fluid UBERON:0000173

Downstream

Neonatal sepsis

Onset of Preterm Parturition

Delivery before 37 weeks, whether by spontaneous labour or by the obstetric decision the rupture forces. It is modelled as a node rather than only as an outcome because three different upstream states reach it - the inflammation that caused the rupture, the infection that followed it, and the barrier failure itself - and the management question is which of them is driving a given pregnancy.

parturition GO:0007567

Downstream

Premature birth

Show evidence (1 reference)

PMID:32785751 SUPPORT REVIEW SYNTHESIS Other

"Inflammatory mediators from damaged membranes are propagated via extracellular vesicles (EV) to maternal uterine tissues and transition quiescent maternal uterine tissues into an active state of labor."

The proposed signalling route from the damaged membrane to myometrial activation, which is the mechanism behind the inflammation-to-parturition edges in this entry. OTHER is kept on purpose: the vesicle-propagation claim is assembled from cell culture and from murine vesicle-transfer experiments, and the review does not say which supports which clause of this sentence, so naming a single evidence type would assert more than the source does. REVIEW_SYNTHESIS records the provenance.

✶

Histopathology

1

Acute Histologic Chorioamnionitis and Funisitis

The pathological correlate of the inflammation nodes, read on the delivered placenta and membranes: neutrophilic infiltration of the choriodecidua, the amnion, the chorionic plate and - when the fetus has mounted its own response - the umbilical cord. What makes the lesion worth recording separately in PPROM rather than folding into the generic chorioamnionitis picture is its distribution. In preterm labour with intact membranes, membranes without demonstrable intraamniotic inflammation show inflammation in the choriodecidua only; in PPROM the same inflammation-negative group already has inflammation in every compartment, including the fetal ones. That is a direct histological argument for this entry's structure, in which the breached barrier and the inflammation are separate nodes and the barrier failure can precede the measurable intraamniotic response rather than follow it.

Show evidence (2 references)

PMID:27090052 SUPPORT Human Clinical

"inflammation appeared in all-compartment0s (choriodeciduitis-46.2 %; amnionitis-23.1 %; funisitis-30.8 %; chorionic-plate inflammation-7.7 %) in IAI(-)/FIRS(-) group with preterm-PROM"

Gives the compartment-by-compartment frequencies in the PPROM cases that had no measurable intraamniotic inflammation, which is the observation that separates this lesion's distribution in PPROM from its distribution in preterm labour.

PMID:27090052 SUPPORT Human Clinical

"We first demonstrated that PTL and preterm-PROM had a different pattern in the involved compartments of acute-HCA and/or funisitis"

States the study's own conclusion, which is the reason this finding is curated on the PPROM entry rather than left to the Chorioamnionitis entry.

⬡

Pathograph

Use the checkboxes to hide or show graph categories. Hover nodes for evidence and cross-linked metadata.

●

Phenotypes

6

Immune 1

Neonatal sepsis HP:0040187

Show evidence (1 reference)

PMID:26564381 REFUTE Human Clinical

"Neonatal sepsis occurred in 23 (2%) of 923 neonates whose mothers were assigned to immediate birth and 29 (3%) of 912 neonates of mothers assigned to expectant management (relative risk [RR] 0·8, 95% CI 0·5-1·3; p=0·37)."

Recorded as REFUTE against the specific claim that waiting after late-preterm PPROM raises neonatal sepsis: the trial was powered for exactly that outcome and did not find it. It does not refute neonatal sepsis as a phenotype of the disease, which the same trial reports in both arms.

Prenatal and Birth 3

Preterm premature rupture of membranes HP:6000310

Show evidence (1 reference)

PMID:28807394 SUPPORT REVIEW SYNTHESIS Human Clinical

"Preterm prelabor rupture of the membranes (pPROM) remains a significant obstetric problem that affects 3-4% of all pregnancies and precedes 40-50% of all preterm births."

Establishes the finding as the entity itself and gives its frequency. Graded as the prevalence item that quotes the same sentence: human epidemiology, collated by a review rather than measured in it.

Oligohydramnios HP:0001562

Sequelae: Pulmonary hypoplasia

Show evidence (1 reference)

PMID:8828433 SUPPORT Human Clinical

"Neonatal mortality and pulmonary hypoplasia were statistically predicted by gestational age at rupture of membranes and interaction of premature rupture of membranes of > 14 days' duration with severe oligohydramnios."

Identifies the interaction - duration crossed with severity - rather than oligohydramnios alone as the predictor, which is what the description records.

Premature birth HP:0001622

Sequelae: Neonatal respiratory distress

Show evidence (1 reference)

PMID:11293640 SUPPORT Human Clinical

"Preterm, prelabour rupture of the fetal membranes (pPROM) is the commonest antecedent of preterm birth, and can lead to death, neonatal disease, and long-term disability."

States the relationship between the entity and this phenotype directly.

Respiratory 2

Pulmonary hypoplasia HP:0002089

Show evidence (1 reference)

PMID:8828433 SUPPORT Human Clinical

"Severe oligohydramnios > 14 days after premature rupture of membranes at < 25 weeks' gestation has a predicted neonatal mortality of > 90%."

The mortality figure attached to the gestational-age and duration thresholds that define the previable subtype.

Neonatal respiratory distress HP:0002643

Show evidence (1 reference)

PMID:26564381 SUPPORT Human Clinical

"neonates born to mothers in the immediate delivery group had increased rates of respiratory distress (76 [8%] of 919 vs 47 [5%] of 910, RR 1·6, 95% CI 1·1-2·30; p=0·008)"

Quantifies the phenotype as the cost of immediate delivery in the late-preterm window, which is the trade-off this entry's treatment section is built around.

🧬

Genetic Associations

1

SERPINH1 (Promoter variant reducing HSP47 expression; susceptibility allele enriched in African ancestry)

Gene: SERPINH1 hgnc:1546 relationship_type: SUSCEPTIBILITY

Show evidence (3 references)

PMID:16938879 SUPPORT Human Clinical

"An initial case-control study demonstrated that the -656 T allele is significantly more frequent in African-American neonates (P < 0.0009) born from pregnancies complicated by PPROM compared with controls (odds ratio of 3.22, 95% confidence interval 1.50, 7.22)."

The clinical association with its effect size, from the discovery case-control study.

PMID:16938879 SUPPORT Human Clinical

"There was no significant difference in ancestry among cases and controls using a dihybrid model based on 29 ancestry-informative markers."

The admixture control. Without it the association in an ancestry-enriched allele would be uninterpretable, so it is cited separately rather than folded into the effect-size item.

PMID:16938879 SUPPORT BACKGROUND In Vitro

"SERPINH1 encodes heat-shock protein 47, a chaperone essential for collagen synthesis."

The gene's function, which is what connects the variant to the collagen-synthesis node. Tagged BACKGROUND because it is established biochemistry restated in the paper's introduction rather than the paper's own result; graded IN_VITRO because the chaperone function it restates was established in cell and biochemical systems, not in the case-control cohort this paper reports.

💊

Medical Actions

4

Latency Antibiotics

Action: Pharmacotherapy NCIT:C15986

Agent: erythromycin CHEBI:48923 ampicillin CHEBI:28971 amoxicillin CHEBI:2676

Platform: Small molecule

A course of antibiotics given after PPROM to prolong the interval to delivery and to reduce neonatal infection and its consequences. Two large randomised trials define it and they do not agree on regimen: the NICHD trial used intravenous ampicillin plus erythromycin followed by oral amoxicillin plus erythromycin, while ORACLE I found the benefit in erythromycin alone and found that co-amoxiclav raised neonatal necrotising enterocolitis. Contemporary practice follows the safety finding rather than the efficacy finding, which is why the amoxicillin component is recorded here with that caveat attached rather than as an equal option.

Mechanism Target:

Ascending Intraamniotic Infection After Rupture — The intended target is the infection that follows the breach, not the mechanism that caused it. That is the honest reading of these trials: they buy latency and reduce neonatal infection, and neither one shows that treating infection prevents rupture.

Show evidence (1 reference)

PMID:32591087 SUPPORT Human Clinical

"Intravenous therapy with clarithromycin was associated with a reduction in the intensity of the intraamniotic inflammatory response in patients with PPROM with either intraamniotic infection or sterile intraamniotic inflammation."

Direct evidence that antibiotic therapy moves the intraamniotic inflammation this edge targets, measured by paired amniocentesis rather than by outcome alone. The agent is clarithromycin, which is not the regimen recorded above.

Show evidence (3 references)

PMID:9307346 SUPPORT Human Clinical

"In the total study population, the primary outcome (44.1 % vs 52.9%; P=.04), respiratory distress (40.5% vs 48.7%; P=.04), and necrotizing enterocolitis (2.3% vs 5.8%; P=.03) were less frequent with antibiotics."

The NICHD trial's primary result, in the 24-32 week window.

PMID:11293640 SUPPORT Human Clinical

"Among the 2260 singletons in this comparison, significantly fewer had the composite primary outcome in the erythromycin group (125 of 1111 [11.2%] vs 166 of 1149 [14.4%], p=0.02)."

ORACLE I's erythromycin result in singletons. Note the same comparison across all infants did not reach significance, which the trial reports separately.

PMID:11293640 REFUTE Human Clinical

"Although co-amoxiclav only and co-amoxiclav plus erythromycin were associated with prolongation of pregnancy, they were also associated with a significantly higher rate of neonatal necrotising enterocolitis."

REFUTE against the claim that co-amoxiclav is an acceptable latency regimen. It does not refute latency antibiotics generally - the same trial supports erythromycin - which is why it is a separate item rather than a qualifier on the one above.

Antenatal Corticosteroids

Action: Pharmacotherapy NCIT:C15986

Agent: betamethasone CHEBI:3077 dexamethasone CHEBI:41879

Platform: Small molecule

A single course of betamethasone or dexamethasone given when preterm delivery is anticipated, to accelerate fetal lung maturation. It is the intervention with the largest and most certain effect on the outcome that carries most of the harm in PPROM, and the concern specific to this population - that a steroid in a pregnancy with ruptured membranes raises maternal infection - is addressed by the same systematic review, which finds little to no difference in chorioamnionitis with wide confidence intervals.

Mechanism Target:

Neonatal respiratory distress — The target is the consequence of prematurity, not any node in the membrane-failure chain. Nothing in this entry's pathophysiology is altered by corticosteroids, and the entry should not be readable as claiming otherwise.

Show evidence (2 references)

PMID:33368142 SUPPORT Human Clinical

"respiratory distress syndrome (RR 0.71, 95% CI 0.65 to 0.78; 11,183 infants; studies = 26; high-certainty evidence; 4.3% fewer, 95% CI 3.2% to 5.2% fewer)"

The pooled effect on the outcome this treatment targets, graded high certainty.

PMID:33368142 NO_EVIDENCE Human Clinical

"The wide 95% CIs in all of these outcomes include possible benefit and possible harm."

Recorded as NO_EVIDENCE against the maternal-infection concern in either direction. The review's own reading of its maternal outcomes, including chorioamnionitis, is that they are imprecise - which is a different statement from safety.

Magnesium Sulphate for Fetal Neuroprotection

Action: Pharmacotherapy NCIT:C15986

Agent: magnesium sulfate CHEBI:32599

Platform: Small molecule

Magnesium sulphate given to a woman at risk of delivering before 34 weeks, to reduce cerebral palsy in the child. Like corticosteroids it treats the consequence of preterm birth rather than the membrane disease, and it is included because PPROM is one of the commonest routes into the population in which it is indicated.

Mechanism Target:

Premature birth — The edge means addresses a consequence of, not prevents. Magnesium sulphate given for neuroprotection does not prolong the pregnancy and is not a tocolytic in this indication - the cited review explicitly excludes trials using it for tocolysis.

Show evidence (2 references)

PMID:38726883 SUPPORT Human Clinical

"magnesium sulphate compared with placebo reduced cerebral palsy (RR 0.71, 95% CI 0.57 to 0.89; 6 RCTs, 6107 children; number needed to treat for additional beneficial outcome (NNTB) 60, 95% CI 41 to 158)"

The pooled effect on cerebral palsy with its number needed to treat, graded high certainty.

PMID:38726883 NO_EVIDENCE Human Clinical

"We did not include studies where magnesium sulphate was used with the primary aim of preterm labour tocolysis, or the prevention and/or treatment of eclampsia."

Recorded as NO_EVIDENCE against reading this treatment as prolonging the pregnancy. The review's exclusion criterion is what makes the neuroprotective indication a separate claim from tocolysis.

Expectant Management with Surveillance

Action: expectant management with maternal and fetal surveillance Ontology label: Therapeutic Procedure NCIT:C49236

Platform: Behavioral / lifestyle

Deferring delivery while watching for infection and fetal compromise. It is the default below 34 weeks and, since the PPROMT trial, also the default between 34 and 37 weeks in the absence of overt infection - a reversal of the previous assumption that the infection risk of waiting outweighed the prematurity risk of delivering. The trial found no reduction in neonatal sepsis from immediate birth and more respiratory distress, more ventilation and longer intensive care; it also found the trade is not free on the maternal side, with more antepartum or intrapartum haemorrhage and intrapartum fever in the expectant arm, against fewer caesareans.

Mechanism Target:

Onset of Preterm Parturition — What is being managed is the timing of delivery, which is the node this edge points at. The intervention is a decision not to intervene, so nothing in the membrane-failure chain upstream of it is touched.

Show evidence (2 references)

PMID:26564381 SUPPORT Human Clinical

"In the absence of overt signs of infection or fetal compromise, a policy of expectant management with appropriate surveillance of maternal and fetal wellbeing should be followed in pregnant women who present with ruptured membranes close to term."

The trial's own interpretation, which is the recommendation this treatment records, with its two explicit preconditions.

PMID:26564381 REFUTE Human Clinical

"those assigned to the expectant management group had higher risks of antepartum or intrapartum haemorrhage (RR 0·6, 95% CI 0·4-0·9), intrapartum fever (0·4, 0·2-0·9), and use of postpartum antibiotics (0·8, 0·7-1·0), and longer hospital stay (p<0·0001), but a lower risk of caesarean delivery (RR..."

REFUTE against any reading of this treatment as costless. The maternal harms sit in the same trial that supports the policy, and are cited from it rather than elsewhere.

🌍

Environmental Factors

1

Maternal Cigarette Smoking

Heavy smoking raises PPROM risk, and the effect is largest at the earliest gestations - roughly fivefold before 28 weeks against twofold before 37. The gestational gradient is what makes this more than an epidemiological association here: it is consistent with an exposure acting on a membrane that has to survive longer, and the same oxidant exposure reproduces the PPROM senescence phenotype in term membranes in vitro.

Show evidence (2 references)

PMID:23329562 SUPPORT Human Clinical

"smoking > 10 cigarettes per day was associated with an increased risk of PPROM at < 28 weeks (odds ratio [OR] 5.28; 95% confidence interval [CI] 2.20 to 12.7)"

The largest effect in the series, from a 17,961-birth retrospective cohort; the same sentence carries the smaller estimates at later gestational ages.

PMID:23329562 NO_EVIDENCE Human Clinical

"Smoking 1 to 10 cigarettes per day was not associated with a significant risk of PPROM at any gestational age."

Recorded as NO_EVIDENCE against any claim that light smoking carries this risk. The exposure is dose-dependent and the entry should not be readable as attributing risk to smoking at any level.

Mechanism Target:

PREDISPOSES Oxidative Stress in the Fetal Membranes — The intermediate is named and has been tested: cigarette smoke extract applied to term fetal membranes raises phospho-p38 MAPK and produces the organelle changes of the senescence phenotype. The human data give the risk; the in vitro data give the step.

Show evidence (1 reference)

PMID:24832021 SUPPORT DIRECT In Vitro

"In vitro cigarette smoke extract exposure increased p-p38 MAPK without any detectable change in p-p53 MAPK."

The measured effect of the exposure on the oxidative-stress and senescence signalling this node models. Quoted with the negative result for p-p53 intact.

🔬

Biochemical Markers

2

Amniotic Fluid Interleukin-6 (INCREASED)

Pathograph Readouts

Readout Of Intraamniotic Inflammatory Response Positive Diagnostic

A raised amniotic fluid IL-6 concentration is what the node is measured by in practice; it is a readout of the inflammation, not a cause of it.

Show evidence (1 reference)

PMID:25758620 SUPPORT Human Clinical

"A POC AF IL-6 test can identify intra-amniotic inflammation in patients with preterm PROM."

States that the marker identifies the node's state in this disease, which is the readout claim this link makes.

Show evidence (1 reference)

PMID:25758620 SUPPORT Human Clinical

"The POC test for AF IL-6 concentrations had 97% sensitivity and 96% specificity for the identification of intra-amniotic inflammation"

Quantifies the bedside assay against the laboratory standard in a PPROM cohort, which is what makes the marker usable at the time the diagnosis is made.

Amniotic Fluid Matrix Metalloproteinase-8 (INCREASED)

Pathograph Readouts

Readout Of Intraamniotic Inflammatory Response Positive Diagnostic

Amniotic fluid MMP-8 above a threshold is the criterion used to call intraamniotic inflammation present in the histopathology study curated above, so it operationalises the same node IL-6 does.

Show evidence (1 reference)

PMID:27090052 SUPPORT Human Clinical

"IAI (amniotic-fluid MMP-8 ≥ 23 ng/ml)"

The threshold at which this cohort called intraamniotic inflammation present, quoted from the study that used it to stratify the placental findings.

Show evidence (1 reference)

PMID:31141489 SUPPORT Human Clinical

"The median values of amniotic fluid MMP-8 concentration and WBC count were the highest in the extreme preterm PROM group and the lowest in the late preterm PROM group"

Establishes the gestational-age gradient in the marker, which is the observation that makes the earliest ruptures the most inflamed rather than merely the most premature. Measured in a cohort restricted to Ureaplasma-positive amniotic fluid, so the gradient is demonstrated within one organism class rather than across all PPROM.

🔬

Diagnosis

5

Sterile Speculum Examination (Positive)

Direct visualisation of amniotic fluid pooling in the posterior vaginal fornix, or of fluid escaping the cervical os, through a speculum passed without digital examination. It is the reference standard and it is also the act that defines the disease clinically: everything else on this list exists for the cases where the speculum finding is equivocal. Digital examination is avoided because it shortens latency and introduces organisms into a cavity that is already open.

sterile speculum examination NCIT:C38104

Results: Visible pooling of amniotic fluid in the posterior fornix or fluid egressing from the cervical os

NCIT has no clinical-action term for speculum examination specifically. NCIT:C17614 Colposcope and NCIT:C88208 Culdoscope name instruments rather than actions and are not reachable from NCIT:C25218; NCIT:C127946 GAIA Level 3 Assessment of Premature Preterm Rupture of Membranes describes this exact finding in its definition but is a case-definition assessment rather than a clinical action. NCIT:C38104 Pelvic Examination is the most specific reachable action term, with the specificity carried in preferred_term.

Show evidence (1 reference)

PMID:41468127 SUPPORT REVIEW SYNTHESIS Human Clinical

"The gold standard for diagnosis is visualizing clear, amniotic fluid egressing from the external cervical os or with an amniocentesis dye test."

Names the reference standard this record encodes, and the invasive alternative that the amniocentesis record below covers.

Nitrazine and Ferning Tests

The two bedside adjuncts read off the same speculum swab: nitrazine paper turning blue on the alkaline pH of amniotic fluid against the acid pH of the normal vagina, and an arborising crystal pattern when a dried smear is examined under the microscope. Together with the examination itself they settle the large majority of presentations. Both are falsifiable by the things that also raise vaginal pH - blood, semen, bacterial vaginosis - which is why they are adjuncts and not the standard.

nitrazine and fern testing of vaginal fluid NCIT:C25294

Markers: Vaginal fluid pH; arborisation (ferning) of a dried vaginal fluid smear

Show evidence (2 references)

PMID:41468127 SUPPORT REVIEW SYNTHESIS Human Clinical

"Greater than 90% of rupture of membrane diagnoses can be made with physical examination, nitrazine testing, and microscopic fern testing."

Quantifies how much of the diagnostic work this record and the speculum record do between them, which is what bounds the role of the immunoassays below.

PMID:27855117 SUPPORT DIRECT Human Clinical

"The specificity and sensitivity values for TCA were 76.2% and 85.2%"

Gives the measured performance of nitrazine, ferning and pooling taken together against a post-delivery reference standard, which is the number that makes the case for an immunoassay in equivocal presentations.

Amniotic Fluid Protein Immunoassay

Bedside immunochromatographic detection of a protein that is abundant in amniotic fluid and scarce in normal cervicovaginal secretions - placental alpha-microglobulin-1 (PAMG-1) or insulin-like growth factor binding protein-1 (IGFBP-1), alone or paired with alpha-fetoprotein. Their place is the equivocal presentation, not the routine one: where the speculum finding is unambiguous they add nothing, and where it is absent they are what prevents either an unnecessary admission or a missed rupture.

cervicovaginal PAMG-1 or IGFBP-1 immunoassay NCIT:C25294

Markers: Placental alpha-microglobulin-1 (PAMG-1); insulin-like growth factor binding protein-1 (IGFBP-1)

Results: Accuracy 98.7% (IGFBP-1) and 93.9% (PAMG-1) against clinical follow-up in PPROM at 20-36 weeks

Show evidence (3 references)

PMID:31099162 SUPPORT DIRECT Human Clinical

"Similar accuracies were observed for IGFBP-1 (98.7%) and PAMG-1 (93.9%)."

Head-to-head accuracy of the two marker proteins in exactly this entry's gestational window, which is why the record names both rather than preferring one.

PMID:31099162 REFUTE Human Clinical

"there is no significant difference between PAMG-1 and traditional tests"

Recorded as REFUTE against the claim that an immunoassay is generally superior to the bedside tests. The same study that gives the accuracy figures above declines to separate PAMG-1 from traditional assessment, and concludes the tests should be used sparingly where they are expensive.

PMID:41468127 SUPPORT REVIEW SYNTHESIS Human Clinical

"Commercial immunoassays should be utilized in equivocal cases to assist in the diagnosis of membrane rupture when the diagnosis is unclear."

Places the immunoassays in the equivocal case rather than in the routine one, which is the scoping claim this record makes.

Obstetric Ultrasound for Amniotic Fluid Volume

Sonographic assessment of residual amniotic fluid. It cannot diagnose the rupture - oligohydramnios has other causes and a recently ruptured sac may still measure normally - but it is what converts a suspected rupture into a confirmed one over the following days, and the residual volume and its persistence are what govern the previable subtype's counselling, since it is prolonged anhydramnios rather than the rupture that produces pulmonary hypoplasia.

obstetric ultrasonography for amniotic fluid volume NCIT:C17230

Results: Reduced or absent amniotic fluid; persistence over serial scans supports the diagnosis

Show evidence (1 reference)

PMID:31099162 SUPPORT INDIRECT Human Clinical

"a diagnosis of PROM was confirmed by a definitive evolution of the clinical symptoms (visualization of vaginal amniotic fluid or persistence of oligohydramnios)"

INDIRECT because the study describes persisting oligohydramnios as one half of its reference standard rather than measuring ultrasound as an index test. That is exactly the role recorded here - a confirmatory observation over time, not a diagnostic test at presentation.

Amniocentesis for Intraamniotic Inflammation and Infection

Transabdominal sampling of amniotic fluid, tested in parallel for organisms and for inflammation. It does not diagnose the rupture; it answers the separate question this entry keeps as a separate node - whether the cavity is inflamed, and whether an organism is recoverable - which is what the expectant-management decision turns on. It is invasive, is not used routinely, and after rupture it is often technically limited by the loss of fluid it is trying to sample.

amniocentesis for amniotic fluid culture and inflammatory markers NCIT:C52009

Markers: Amniotic fluid interleukin-6; matrix metalloproteinase-8; white blood cell count; Gram stain and culture

Show evidence (1 reference)

PMID:25758620 SUPPORT Human Clinical

"Amniocentesis was performed at the time of diagnosis, and AF was analyzed using cultivation techniques for aerobic and anaerobic bacteria as well as genital mycoplasmas."

Describes the procedure and the parallel microbiological testing in a PPROM cohort, which is the practice this record models and the source of the biomarkers curated in the biochemical section.

📊

Prevalence

2

Worldwide

Point Prevalence 3500.0 per 100,000 (3000.0–4000.0) >1 in 1,000

3-4% of pregnancies. The denominator is pregnancies, not the general population, so this is a per-pregnancy occurrence rate and is not comparable with a population prevalence.

Show evidence (1 reference)

PMID:28807394 SUPPORT REVIEW SYNTHESIS Human Clinical

"Preterm prelabor rupture of the membranes (pPROM) remains a significant obstetric problem that affects 3-4% of all pregnancies and precedes 40-50% of all preterm births."

Gives both the per-pregnancy rate recorded here and the fraction of preterm births it precedes, which is the figure that sets this entry's burden. The quoted text is human population epidemiology, so it is graded HUMAN_CLINICAL; REVIEW_SYNTHESIS records that this review is collating figures generated elsewhere rather than reporting a cohort of its own.

Preterm deliveries

Point Prevalence 35000.0 per 100,000 (30000.0–40000.0) >1 in 1,000

The conditional fraction - 30-40% of preterm deliveries follow PPROM - not a population figure. Recorded because it is the number that makes this entry a high-burden one. Note the two cited sources give 30-40% (1998) and 40-50% (2017) for the same quantity; both are recorded rather than averaged.

Show evidence (1 reference)

PMID:9822510 SUPPORT Human Clinical

"Preterm premature rupture of fetal membranes is responsible for 30% to 40% of preterm deliveries."

The conditional fraction of preterm deliveries attributable to PPROM.

⚖️

Clinical Burden

High

PPROM is the commonest identifiable antecedent of preterm birth, which is itself the leading cause of neonatal death worldwide. The burden is almost entirely transmitted: the rupture harms nobody directly, but it delivers the fetus early, opens the amniotic cavity to ascending infection, and - when it happens early enough and lasts long enough - removes the amniotic fluid that fetal lung development requires.

Show evidence (2 references)

PMID:11293640 SUPPORT Human Clinical

"Preterm, prelabour rupture of the fetal membranes (pPROM) is the commonest antecedent of preterm birth, and can lead to death, neonatal disease, and long-term disability."

States the burden claim directly, from the largest randomised trial in the condition.

PMID:8828433 SUPPORT Human Clinical

"Both duration of severe oligohydramnios exposure and gestational age at premature rupture of membranes were independent significant predictors of increased neonatal risk."

Identifies the two variables that govern outcome, which is why this entry models gestational age at rupture and latency duration rather than rupture alone.

🔀

Differential Diagnoses

4

Conditions with similar clinical presentations that must be differentiated from Preterm Premature Rupture of the Membranes:

Urinary incontinence in pregnancy

Overlapping Features The commonest benign explanation for reported fluid loss in the third trimester, and the one that makes sterile speculum confirmation rather than history the diagnostic step.

Increased physiological vaginal discharge

Overlapping Features Leucorrhoea increases in late pregnancy and is reported as wetness. It is distinguished on speculum examination by the absence of pooling.

Term premature rupture of the membranes

Overlapping Features The same lesion at or after 37 weeks. It is a different entity for management purposes - induction rather than latency - and the mechanism literature treats term rupture as the physiological endpoint of the same senescence process rather than as a disease.

Placental abruption

Overlapping Features Shares a mechanism with PPROM through decidual haemorrhage and thrombin, and the two co-occur, so it is a differential and a comorbidity at once. It is distinguished by pain, bleeding and uterine tone rather than by fluid loss.

🔬

Clinical Trials

1

ISRCTN44485060 NOT_APPLICABLE COMPLETED

The PPROMT trial - immediate delivery versus expectant management for PPROM between 34 weeks and 36 weeks and 6 days, with neonatal sepsis as the primary outcome. It has no NCT identifier: it is registered on ISRCTN and reached here through the WHO ICTRP, which is the identifier the publication itself cites. `phase` follows the registry's own Not Applicable value rather than assigning a phase the register does not claim.

Target Phenotypes: Neonatal sepsis HP:0040187 Neonatal respiratory distress HP:0002643

Show evidence (2 references)

ICTRP:ISRCTN44485060 SUPPORT Other

"Current inclusion criteria as of 12/02/2009: Singleton pregnancies, with confirmed ruptured membranes from 34 weeks to 36 weeks and 6 days gestation."

WHO ICTRP registration record establishing the trial's identity and its registered eligibility window, which is the window the late-preterm subtype names. OTHER is the right grade and no quote_role applies: a registration document is not study evidence and has no argument of its own for the quote to sit in.

PMID:26564381 SUPPORT Human Clinical

"The PPROMT trial was a multicentre randomised controlled trial done at 65 centres across 11 countries."

Establishes the trial's design and scale, from the primary report.

{ }

Source YAML

click to show

name: Preterm Premature Rupture of the Membranes
creation_date: "2026-09-19T00:00:00Z"
category: Complex
synonyms:
- PPROM
- pPROM
- Preterm prelabor rupture of the membranes
- Preterm prelabour rupture of fetal membranes
- Preterm premature rupture of the fetal membranes
description: >-
  Preterm premature rupture of the membranes is the failure of a load-bearing tissue,
  and that is the useful way to read it: the amniochorion is an avascular collagen
  sheet that has to hold for forty weeks and then give way, and in PPROM it gives way
  early. It complicates 3-4% of pregnancies and precedes 40-50% of all preterm births,
  which makes it the largest single identifiable route to the leading cause of neonatal
  death worldwide. The contemporary model treats it as a disease of the fetal membranes
  rather than as an early instance of labour: oxidative stress accumulates in the
  amniochorion, drives premature cellular senescence with its associated secretory
  phenotype, and both the senescence-derived sterile inflammation and any ascending
  microbial inflammation converge on matrix metalloproteinase activity that degrades
  the fibrillar collagen holding the sheet together. Microfractures - channels through
  areas the amnion has vacated - are more numerous, wider and deeper in PPROM membranes
  than in gestational-age-matched spontaneous preterm birth, marking remodelling that
  failed rather than remodelling that succeeded. The same convergence can be reached
  from the maternal side by decidual haemorrhage, where thrombin overrides the
  progestin suppression of collagenase and links placental abruption to membrane
  rupture. Once the sheet fails, the pathology changes character entirely and becomes a
  problem of a breached barrier: amniotic fluid is lost, the cavity is open to ascending
  organisms, and the fetus is delivered preterm either by the inflammation that caused
  the rupture or by the obstetric decision the rupture forces. Almost all of the
  management - latency antibiotics, antenatal corticosteroids, magnesium sulphate,
  expectant management where it is safe - buys gestational age against infection, and
  the trials that define it are trials of that trade rather than of the mechanism.
disease_term:
  preferred_term: preterm premature rupture of the membranes
  term:
    id: MONDO:0012511
    label: preterm premature rupture of the membranes
parents:
- Fetal membrane disorder
- Obstetric disorder
classifications:
  harrisons_chapter:
  - classification_value: OTHER
mappings:
  icd10cm_mappings:
  - term:
      id: ICD10CM:O42.919
      label: Preterm premature rupture of membranes, unspecified as to length of time between rupture and onset of labor, unspecified trimester
    mapping_predicate: skos:closeMatch
    mapping_source: ICD10CM
    mapping_justification: >-
      The single ICD-10-CM code that names preterm premature rupture of the membranes
      with both of its qualifying axes left unspecified, which is the nearest coded
      equivalent of this entry's disease unit. closeMatch rather than exactMatch because
      the code remains a member of a latency-stratified family: ICD-10-CM cuts PPROM
      along two axes this entry does not use - the interval between rupture and the onset
      of labour, and the trimester - giving nine preterm codes (O42.011-O42.019,
      O42.111-O42.119, O42.911-O42.919). Mapping all nine would assert nine disease units
      where this entry curates one, so a claims query should expand to that family rather
      than read this mapping as exhaustive.
  - term:
      id: ICD10CM:O42
      label: Premature rupture of membranes
    mapping_predicate: skos:broadMatch
    mapping_source: ICD10CM
    mapping_justification: >-
      The ICD-10-CM category covering rupture of the membranes before labour at any
      gestation. It is broader than this entry, which is restricted to rupture before 37
      weeks: O42.02, O42.12 and O42.92 code the full-term case, which this entry treats
      as a differential diagnosis rather than as itself.
references:
- reference: PMID:28807394
  title: "Preterm prelabor rupture of the membranes: A disease of the fetal membranes."
- reference: PMID:32785751
  title: Novel pathways of inflammation in human fetal membranes associated with preterm birth and preterm pre-labor rupture of the membranes.
- reference: PMID:18205191
  title: "A 12-bp deletion in the 5'-flanking region of the SERPINH1 gene affects promoter activity and protects against preterm premature rupture of membranes in African Americans."
has_subtypes:
- name: Previable
  display_name: Previable PPROM (rupture before about 23 weeks)
  description: >-
    Rupture before the threshold of viability. It is separated from the others because
    the dominant pathology is not prematurity but the consequence of prolonged
    anhydramnios during the canalicular phase of lung development: pulmonary hypoplasia
    and skeletal deformation, on top of a high rate of intrauterine loss. The
    counselling and the management decision are categorically different from later
    PPROM, which is why this is a subtype rather than a severity grade.
  evidence:
  - reference: PMID:8828433
    reference_title: "Defining limits of survival: lethal pulmonary hypoplasia after midtrimester premature rupture of membranes."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Severe oligohydramnios > 14 days after premature rupture of membranes at < 25 weeks' gestation has a predicted neonatal mortality of > 90%."
    explanation: >-
      Quantifies the outcome that distinguishes this subtype - mortality driven by
      duration of severe oligohydramnios and gestational age at rupture, not by the
      rupture itself.
- name: Early-Preterm
  display_name: Early-preterm PPROM (about 23 to 33 weeks)
  description: >-
    The gestational window in which latency antibiotics, antenatal corticosteroids and
    magnesium sulphate are all indicated and in which prolonging the pregnancy is worth
    the infection risk. The randomised evidence that defines expectant management with
    antibiotics was generated in this window.
  evidence:
  - reference: PMID:9307346
    reference_title: Antibiotic therapy for reduction of infant morbidity after preterm premature rupture of the membranes. A randomized controlled trial. National Institute of Child Health and Human Development Maternal-Fetal Medicine Units Network.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "A total of 614 of 804 eligible gravidas with PPROM between 24 weeks' and 0 days' and 32 weeks' and 0 days' gestation who were considered candidates for pregnancy prolongation"
    explanation: >-
      Defines the gestational window of the trial that established latency antibiotics,
      which is the window this subtype names.
- name: Late-Preterm
  display_name: Late-preterm PPROM (34 to 36 weeks and 6 days)
  description: >-
    Rupture close to term, where the balance flips: the fetus is mature enough that the
    infection risk of waiting was long assumed to outweigh the prematurity risk of
    delivering. The PPROMT trial tested exactly that assumption in this window and
    found against it, which is why the window is worth separating.
  evidence:
  - reference: PMID:26564381
    reference_title: "Immediate delivery compared with expectant management after preterm pre-labour rupture of the membranes close to term (PPROMT trial): a randomised controlled trial."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Women aged over 16 years with singleton pregnancies and ruptured membranes before the onset of labour between 34 weeks and 36 weeks and 6 days weeks who had no signs of infection were included."
    explanation: States the gestational bounds that define this subtype, as used by the trial that governs its management.
prevalence:
- population: Worldwide
  measure_type: POINT_PREVALENCE
  prevalence_class: ABOVE_1_IN_1000
  rate_per_100000: 3500.0
  rate_low: 3000.0
  rate_high: 4000.0
  notes: >-
    3-4% of pregnancies. The denominator is pregnancies, not the general population, so
    this is a per-pregnancy occurrence rate and is not comparable with a population
    prevalence.
  evidence:
  - reference: PMID:28807394
    reference_title: "Preterm prelabor rupture of the membranes: A disease of the fetal membranes."
    supports: SUPPORT
    quote_role: REVIEW_SYNTHESIS
    evidence_source: HUMAN_CLINICAL
    snippet: "Preterm prelabor rupture of the membranes (pPROM) remains a significant obstetric problem that affects 3-4% of all pregnancies and precedes 40-50% of all preterm births."
    explanation: >-
      Gives both the per-pregnancy rate recorded here and the fraction of preterm births
      it precedes, which is the figure that sets this entry's burden. The quoted text is
      human population epidemiology, so it is graded HUMAN_CLINICAL; REVIEW_SYNTHESIS
      records that this review is collating figures generated elsewhere rather than
      reporting a cohort of its own.
- population: Preterm deliveries
  measure_type: POINT_PREVALENCE
  prevalence_class: ABOVE_1_IN_1000
  rate_per_100000: 35000.0
  rate_low: 30000.0
  rate_high: 40000.0
  notes: >-
    The conditional fraction - 30-40% of preterm deliveries follow PPROM - not a
    population figure. Recorded because it is the number that makes this entry a
    high-burden one. Note the two cited sources give 30-40% (1998) and 40-50% (2017)
    for the same quantity; both are recorded rather than averaged.
  evidence:
  - reference: PMID:9822510
    reference_title: A role for matrix metalloproteinase-9 in spontaneous rupture of the fetal membranes.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Preterm premature rupture of fetal membranes is responsible for 30% to 40% of preterm deliveries."
    explanation: The conditional fraction of preterm deliveries attributable to PPROM.
clinical_burden:
  burden_level: HIGH
  rationale: >-
    PPROM is the commonest identifiable antecedent of preterm birth, which is itself the
    leading cause of neonatal death worldwide. The burden is almost entirely
    transmitted: the rupture harms nobody directly, but it delivers the fetus early,
    opens the amniotic cavity to ascending infection, and - when it happens early enough
    and lasts long enough - removes the amniotic fluid that fetal lung development
    requires.
  evidence:
  - reference: PMID:11293640
    reference_title: "Broad-spectrum antibiotics for preterm, prelabour rupture of fetal membranes: the ORACLE I randomised trial. ORACLE Collaborative Group."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Preterm, prelabour rupture of the fetal membranes (pPROM) is the commonest antecedent of preterm birth, and can lead to death, neonatal disease, and long-term disability."
    explanation: States the burden claim directly, from the largest randomised trial in the condition.
  - reference: PMID:8828433
    reference_title: "Defining limits of survival: lethal pulmonary hypoplasia after midtrimester premature rupture of membranes."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Both duration of severe oligohydramnios exposure and gestational age at premature rupture of membranes were independent significant predictors of increased neonatal risk."
    explanation: >-
      Identifies the two variables that govern outcome, which is why this entry models
      gestational age at rupture and latency duration rather than rupture alone.
pathophysiology:
- name: Oxidative Stress in the Fetal Membranes
  conforms_to: "cellular_senescence#Senescence-Inducing Stress"
  biological_scale: CELLULAR
  description: >-
    Reactive oxygen species accumulate in the amniochorion during gestation and are
    accelerated by risk-factor exposures. This is the node the contemporary model puts
    upstream of everything else in the non-infectious route to PPROM, and it is also the
    node at which the main modifiable risk factor - smoking - acts.
  cell_types:
  - preferred_term: epithelial cell of amnion
    term:
      id: CL:0002536
      label: epithelial cell of amnion
  - preferred_term: amnion mesenchymal fibroblast
    term:
      id: CL:0000057
      label: fibroblast
  biological_processes:
  - preferred_term: response to oxidative stress
    modifier: INCREASED
    term:
      id: GO:0006979
      label: response to oxidative stress
  locations:
  - preferred_term: amnion
    term:
      id: UBERON:0000305
      label: amnion
  - preferred_term: chorion membrane
    term:
      id: UBERON:0003124
      label: chorion membrane
  evidence:
  - reference: PMID:32785751
    reference_title: Novel pathways of inflammation in human fetal membranes associated with preterm birth and preterm pre-labor rupture of the membranes.
    supports: SUPPORT
    quote_role: REVIEW_SYNTHESIS
    evidence_source: IN_VITRO
    snippet: "The intrauterine build-up of oxidative stress at term or in response to risk factors (preterm) can accelerate senescence and promote a terminal state of EMT, resulting in the accumulation of inflammation."
    explanation: >-
      States the oxidative-stress-to-senescence-to-inflammation sequence that the next
      two nodes model, and marks the preterm case as risk-factor driven. The
      acceleration claim rests on oxidant exposure of cultured fetal membrane cells and
      organ explants - the same experimental route as PMID:24832021 on the edge below -
      so it is graded IN_VITRO, with REVIEW_SYNTHESIS recording that this review did not
      perform those experiments.
  downstream:
  - target: Premature Senescence of the Amniochorion
    causal_link_type: DIRECT
    description: >-
      The strongest experimental support is that the senescence phenotype can be induced
      in term membranes in vitro by an oxidant exposure, which makes this an inducible
      relationship rather than only a correlated one.
    evidence:
    - reference: PMID:24832021
      reference_title: Histological evidence of oxidative stress and premature senescence in preterm premature rupture of the human fetal membranes recapitulated in vitro.
      supports: SUPPORT
      directness: DIRECT
      evidence_source: IN_VITRO
      snippet: "Histologic and biochemical resemblance of pPROM and term membranes suggests premature senescence of the membranes is a mechanistic feature in pPROM, and this can be phenocopied in an in vitro model."
      explanation: >-
        The in vitro phenocopy is what turns the histological association into a causal
        claim about oxidative stress driving the senescence node.
- name: Premature Senescence of the Amniochorion
  conforms_to: "cellular_senescence#Senescence-Associated Cell Cycle Arrest"
  biological_scale: CELLULAR
  description: >-
    Fetal membrane cells in PPROM carry the senescence markers p53, p21 and
    phospho-p38 MAPK at frequencies resembling term membranes rather than
    gestational-age-matched preterm ones - the membranes have aged early. Fetal
    telomere length points the same way. The clinical reading is that PPROM membranes
    have reached, prematurely, the state that normally permits rupture at term.
  cell_types:
  - preferred_term: epithelial cell of amnion
    term:
      id: CL:0002536
      label: epithelial cell of amnion
  biological_processes:
  - preferred_term: cellular senescence
    modifier: INCREASED
    term:
      id: GO:0090398
      label: cellular senescence
  locations:
  - preferred_term: amnion
    term:
      id: UBERON:0000305
      label: amnion
  evidence:
  - reference: PMID:24832021
    reference_title: Histological evidence of oxidative stress and premature senescence in preterm premature rupture of the human fetal membranes recapitulated in vitro.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "A total of 80% of pPROM cells and >60% of term cells were positive for all three senescence phenotype markers, and concentrations were higher than in PTBs (P < 0.05)."
    explanation: >-
      The comparator is the informative part: PPROM membranes resemble term membranes
      and differ from gestational-age-matched spontaneous preterm birth, which is what
      makes this specific to PPROM rather than to prematurity.
  - reference: PMID:22348044
    reference_title: Short fetal leukocyte telomere length and preterm prelabor rupture of the membranes.
    supports: SUPPORT
    directness: INDIRECT
    evidence_source: HUMAN_CLINICAL
    snippet: "pPROM had telomere lengths (9962 ± 3124 bp) that were significantly shorter than gestational age-matched PTB (11546 ± 4348 bp, p = 0.04), but comparable to term births (9011 ± 2497 bp, p = 0.31)."
    explanation: >-
      A second, independent marker of the same early-ageing pattern. INDIRECT because
      telomere length is a surrogate for oxidative stress and senescence rather than a
      measurement of the membrane state itself, and because it was measured in cord
      blood leukocytes - the study reports a strong correlation with placental membrane
      telomere length, which is the step that licenses the inference.
  downstream:
  - target: Microfracture Formation in the Amnion
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
    description: >-
      Microfractures appear as extensions of areas the amnion has vacated through
      shedding or senescence-associated topographic change. The cited source postulates
      the link rather than demonstrating it, and says so.
  - target: Intraamniotic Inflammatory Response
    causal_link_type: DIRECT
    description: >-
      The senescence-associated secretory phenotype is the proposed source of the
      sterile intraamniotic inflammation seen in PPROM without microbial invasion. This
      is the edge that makes a single model cover both the infected and the
      culture-negative cases.
- name: Ascending Choriodecidual Microbial Colonization
  biological_scale: TISSUE
  description: >-
    Organisms ascend from the lower genital tract into the choriodecidual space and, in
    a subset, into the amniotic cavity. This is the classic route and it remains the one
    the treatment is aimed at, but it is not the only route: a substantial fraction of
    PPROM has intraamniotic inflammation with no recoverable organism, which is why the
    inflammation node below is kept separate from this one.
  cell_types:
  - preferred_term: decidual cell
    term:
      id: CL:2000002
      label: decidual cell
  - preferred_term: neutrophil
    term:
      id: CL:0000775
      label: neutrophil
  locations:
  - preferred_term: decidua
    term:
      id: UBERON:0002450
      label: decidua
  - preferred_term: amniotic fluid
    term:
      id: UBERON:0000173
      label: amniotic fluid
  evidence:
  - reference: PMID:9307346
    reference_title: Antibiotic therapy for reduction of infant morbidity after preterm premature rupture of the membranes. A randomized controlled trial. National Institute of Child Health and Human Development Maternal-Fetal Medicine Units Network.
    supports: SUPPORT
    quote_role: BACKGROUND
    evidence_source: HUMAN_CLINICAL
    snippet: "Intrauterine infection is thought to be one cause of preterm premature rupture of the membranes (PPROM)."
    explanation: >-
      Records the hypothesis at the strength its own source states it - thought to be
      one cause. Tagged BACKGROUND because it is the trial's framing sentence, not its
      result; the trial's result is cited on the antibiotic treatment. The sentence
      summarises human clinical observation, so HUMAN_CLINICAL + BACKGROUND is the pair
      that is true of it - OTHER would have asserted nothing about the evidence.
  downstream:
  - target: Intraamniotic Inflammatory Response
    causal_link_type: DIRECT
- name: Intraamniotic Inflammatory Response
  biological_scale: TISSUE
  description: >-
    Raised amniotic fluid interleukin-6 with or without recoverable organisms. The
    distinction is operationalised in the literature and matters here: intraamniotic
    infection is microbial invasion plus inflammation, whereas sterile intraamniotic
    inflammation is inflammation without invasion. Both drive the same downstream
    proteolysis, which is why this entry models the inflammation rather than the
    infection as the pathogenic node.
  cell_types:
  - preferred_term: neutrophil
    term:
      id: CL:0000775
      label: neutrophil
  - preferred_term: macrophage
    term:
      id: CL:0000235
      label: macrophage
  biological_processes:
  - preferred_term: inflammatory response
    modifier: INCREASED
    term:
      id: GO:0006954
      label: inflammatory response
  - preferred_term: cytokine-mediated signaling pathway
    modifier: INCREASED
    term:
      id: GO:0019221
      label: cytokine-mediated signaling pathway
  locations:
  - preferred_term: amniotic fluid
    term:
      id: UBERON:0000173
      label: amniotic fluid
  evidence:
  - reference: PMID:32591087
    reference_title: Antibiotic administration reduces the rate of intraamniotic inflammation in preterm prelabor rupture of the membranes.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Intraamniotic infection was defined as the presence of both microbial invasion of the amniotic cavity and intraamniotic inflammation; sterile intraamniotic inflammation was defined as the presence of intraamniotic inflammation without microbial invasion of the amniotic cavity."
    explanation: >-
      The operational definitions that separate the infected from the sterile route, both
      of which this node covers.
  - reference: PMID:32785751
    reference_title: Novel pathways of inflammation in human fetal membranes associated with preterm birth and preterm pre-labor rupture of the membranes.
    supports: SUPPORT
    quote_role: REVIEW_SYNTHESIS
    evidence_source: IN_VITRO
    snippet: "Inflammation degrades the matrix and destabilizes membrane function."
    explanation: >-
      States the inflammation-to-matrix step that the downstream edge asserts. The
      degradation and mechanical-destabilisation work behind the sentence is done on
      cultured fetal membrane explants, so it is graded IN_VITRO rather than OTHER, and
      REVIEW_SYNTHESIS records that the citing publication is a review.
  downstream:
  - target: Matrix Metalloproteinase-Mediated Collagen Degradation in the Amniochorion
    causal_link_type: DIRECT
    evidence:
    - reference: PMID:9822510
      reference_title: A role for matrix metalloproteinase-9 in spontaneous rupture of the fetal membranes.
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "Women with microbial invasion of the amniotic cavity had higher median matrix metalloproteinase-9 concentrations than did those without microbial invasion regardless of membrane status"
      explanation: >-
        Links the infectious arm of the inflammation node to the MMP-9 node, and does so
        independently of membrane status - so the association is not merely a consequence
        of the rupture having already happened.
  - target: Onset of Preterm Parturition
    causal_link_type: DIRECT
    description: >-
      Intraamniotic inflammation activates the myometrium as well as degrading the
      membranes, so an inflamed pregnancy can reach preterm delivery without waiting for
      the barrier failure. This is the edge that makes latency finite even when the
      rupture is managed perfectly.
- name: Decidual Haemorrhage and Thrombin Generation
  biological_scale: TISSUE
  description: >-
    Bleeding at the decidual interface generates thrombin, which overrides the
    progestin suppression of collagenase expression in decidual cells. This is a
    maternal-side entry into the same proteolytic node and is the mechanistic account of
    why placental abruption and PPROM travel together clinically.
  cell_types:
  - preferred_term: decidual cell
    term:
      id: CL:2000002
      label: decidual cell
  locations:
  - preferred_term: decidua
    term:
      id: UBERON:0002450
      label: decidua
  evidence:
  - reference: PMID:12380602
    reference_title: "Thrombin-enhanced matrix metalloproteinase-1 expression: a mechanism linking placental abruption with premature rupture of the membranes."
    supports: SUPPORT
    directness: INDIRECT
    evidence_source: IN_VITRO
    snippet: "MPA strongly inhibited MMP-1 levels in endometrial stromal and term decidual cells. However, thrombin overcame this suppression, producing MMP-1 levels that were several-fold higher than control levels."
    explanation: >-
      The measured result: thrombin defeats the progestin brake on interstitial
      collagenase. INDIRECT because it is cultured cells under a hormonal mimic, and the
      authors themselves describe the step to the pregnant state as an extrapolation.
  downstream:
  - target: Matrix Metalloproteinase-Mediated Collagen Degradation in the Amniochorion
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
    evidence:
    - reference: PMID:12380602
      reference_title: "Thrombin-enhanced matrix metalloproteinase-1 expression: a mechanism linking placental abruption with premature rupture of the membranes."
      supports: SUPPORT
      directness: INDIRECT
      evidence_source: IN_VITRO
      snippet: "Extrapolation of thrombin-enhanced MMP-1 expression in cultured endometrial stromal and decidual cells to the in vivo pregnant state provides an explanation for the strong association between placental abruption and preterm membrane rupture."
      explanation: >-
        Quoted with its own hedge intact - the authors label the move to the in vivo
        pregnant state an extrapolation, which is why this edge is not DIRECT.
- name: Reduced Amnion Collagen Synthesis
  biological_scale: MOLECULAR
  description: >-
    Amnion fibroblasts lay down the fibrillar collagen that gives the sheet its tensile
    strength, and that synthesis depends on the collagen-specific chaperone HSP47,
    encoded by SERPINH1. A promoter allele that lowers SERPINH1 transcription is the one
    genetic finding in PPROM that has both an effect on the molecule and a replicated
    clinical association, so this node is the genetic entry point into the same
    structural failure the proteolytic nodes reach from the other direction.
  genes:
  - preferred_term: SERPINH1
    term:
      id: hgnc:1546
      label: SERPINH1
  cell_types:
  - preferred_term: amnion mesenchymal fibroblast
    term:
      id: CL:0000057
      label: fibroblast
  biological_processes:
  - preferred_term: collagen biosynthetic process
    modifier: DECREASED
    term:
      id: GO:0032964
      label: collagen biosynthetic process
  - preferred_term: protein folding
    modifier: DECREASED
    term:
      id: GO:0006457
      label: protein folding
  locations:
  - preferred_term: amnion
    term:
      id: UBERON:0000305
      label: amnion
  evidence:
  - reference: PMID:16938879
    reference_title: A functional SNP in the promoter of the SERPINH1 gene increases risk of preterm premature rupture of membranes in African Americans.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The -656 T allele displayed significantly reduced promoter activity compared to the major -656 C allele in amnion fibroblasts, which lay down the fibrillar collagen that gives tensile strength to the amnion."
    explanation: >-
      Gives both halves of this node in one sentence: the molecular effect of the allele
      and the reason amnion fibroblast collagen is the load-bearing element.
  downstream:
  - target: Loss of Amniochorion Tensile Strength
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
    description: >-
      Reduced chaperone availability to reduced tensile strength is the plausible and
      intended reading of the genetic finding, but no study measures membrane tensile
      strength as a function of SERPINH1 genotype. The edge is recorded at that strength.
- name: Matrix Metalloproteinase-Mediated Collagen Degradation in the Amniochorion
  biological_scale: MOLECULAR
  description: >-
    MMP-9 (gelatinase B) rises in amniotic fluid around membrane rupture, and MMP-1
    (interstitial collagenase) is the thrombin-inducible arm. The relevant quantity is
    protease activity against the tissue inhibitors of metalloproteinases rather than
    either alone. This is the convergence node: the infectious, sterile-inflammatory and
    haemorrhagic routes all arrive here.
  genes:
  - preferred_term: MMP9
    term:
      id: hgnc:7176
      label: MMP9
  - preferred_term: MMP1
    term:
      id: hgnc:7155
      label: MMP1
  - preferred_term: TIMP1
    term:
      id: hgnc:11820
      label: TIMP1
  biological_processes:
  - preferred_term: collagen catabolic process
    modifier: INCREASED
    term:
      id: GO:0030574
      label: collagen catabolic process
  - preferred_term: extracellular matrix disassembly
    modifier: INCREASED
    term:
      id: GO:0022617
      label: extracellular matrix disassembly
  locations:
  - preferred_term: amnion
    term:
      id: UBERON:0000305
      label: amnion
  - preferred_term: chorion membrane
    term:
      id: UBERON:0003124
      label: chorion membrane
  evidence:
  - reference: PMID:9822510
    reference_title: A role for matrix metalloproteinase-9 in spontaneous rupture of the fetal membranes.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Our data support a role for matrix metalloproteinase-9 in the mechanisms responsible for membrane rupture in term and preterm gestations."
    explanation: >-
      The authors' own conclusion from amniotic fluid measurements across 201 women in
      six clinically defined groups.
  - reference: PMID:9822510
    reference_title: A role for matrix metalloproteinase-9 in spontaneous rupture of the fetal membranes.
    supports: SUPPORT
    quote_role: BACKGROUND
    evidence_source: IN_VITRO
    snippet: "Matrix metalloproteinases are enzymes capable of degrading extracellular matrix macromolecules, including collagens."
    explanation: >-
      The substrate rationale for the node. Tagged BACKGROUND because it is the paper's
      framing of established biochemistry rather than its own measurement. What the
      sentence describes is enzyme activity on matrix substrates - a biochemical assay
      outside an organism - so IN_VITRO is what it is evidence of, even though the
      citing paper is a human cross-sectional study.
  downstream:
  - target: Loss of Amniochorion Tensile Strength
    causal_link_type: DIRECT
- name: Microfracture Formation in the Amnion
  biological_scale: TISSUE
  description: >-
    Microfractures are channels or tunnels through the amnion, visible by nonlinear
    microscopy, that appear where amnion cells have been shed or the surface has been
    altered by senescence. They are present in normal membranes too and are read as
    sites of ordinary remodelling; what distinguishes PPROM is that there are more of
    them and they are wider and deeper, which is interpreted as remodelling that failed.
    They matter twice over, as a structural defect and as a conduit.
  locations:
  - preferred_term: amnion
    term:
      id: UBERON:0000305
      label: amnion
  evidence:
  - reference: PMID:28807394
    reference_title: "Preterm prelabor rupture of the membranes: A disease of the fetal membranes."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The number of microfractures and their dimensions (wider and deeper) are significantly higher in fetal membranes from pPROM than gestational age matched sPTB tissues."
    explanation: >-
      The comparison that makes microfractures specific to PPROM rather than to preterm
      delivery in general.
  - reference: PMID:28807394
    reference_title: "Preterm prelabor rupture of the membranes: A disease of the fetal membranes."
    supports: SUPPORT
    quote_role: REVIEW_SYNTHESIS
    evidence_source: HUMAN_CLINICAL
    snippet: "Microfractures can act as channels for amniotic fluid leak, and inflammatory cell and microbial migration."
    explanation: >-
      The conduit reading, which is the proposed route by which a structural defect
      becomes both a leak and an infection pathway before frank rupture. Graded to match
      the measurement item above it: the same imaging of human PPROM membranes, read
      functionally. REVIEW_SYNTHESIS marks it as the review's interpretation, which is
      also why the edge below it is recorded as INDIRECT_UNKNOWN_INTERMEDIATES.
  downstream:
  - target: Loss of Amniochorion Tensile Strength
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
    description: >-
      The source postulates that microfractures mark insufficient or ineffective
      remodelling rather than demonstrating that they cause the sheet to fail, and the
      edge is recorded at that strength.
- name: Loss of Amniochorion Tensile Strength
  biological_scale: TISSUE
  description: >-
    The mechanical endpoint of every upstream branch: the amniochorion can no longer
    carry the load it is subjected to. Keeping this node separate from rupture itself is
    deliberate - it is the state a membrane can be in for days or weeks before it gives
    way, and it is the state a biomarker or imaging test would have to detect to be
    useful before the event.
  biological_processes:
  - preferred_term: collagen fibril organization
    modifier: DECREASED
    term:
      id: GO:0030199
      label: collagen fibril organization
  locations:
  - preferred_term: amnion
    term:
      id: UBERON:0000305
      label: amnion
  - preferred_term: chorion membrane
    term:
      id: UBERON:0003124
      label: chorion membrane
  evidence:
  - reference: PMID:28807394
    reference_title: "Preterm prelabor rupture of the membranes: A disease of the fetal membranes."
    supports: SUPPORT
    quote_role: REVIEW_SYNTHESIS
    evidence_source: OTHER
    snippet: "we introduce the concept that pPROM is a disease of the fetal membranes where inflammation-oxidative stress axis plays a major role in producing pathways that can lead to membrane weakening through a variety of processes"
    explanation: >-
      The framing claim this node encodes - that the several upstream pathways converge
      on membrane weakening - stated by the review that proposes it. OTHER is retained
      deliberately here: the sentence introduces a conceptual model and describes no
      study, so there is no evidence type to grade, and REVIEW_SYNTHESIS now carries the
      fact that this is the review's own synthesis.
  downstream:
  - target: Rupture of the Chorioamniotic Membranes Before 37 Weeks
    causal_link_type: DIRECT
- name: Rupture of the Chorioamniotic Membranes Before 37 Weeks
  biological_scale: TISSUE
  description: >-
    The defining lesion, and the point at which the disease changes character. Up to
    here the pathology is a progressive weakening of one tissue; from here it is a
    breached barrier, and what follows is driven by what the breach allows rather than
    by what caused it.
  locations:
  - preferred_term: amnion
    term:
      id: UBERON:0000305
      label: amnion
  - preferred_term: chorion membrane
    term:
      id: UBERON:0003124
      label: chorion membrane
  downstream:
  - target: Preterm premature rupture of membranes
    causal_link_type: DIRECT
    description: The clinically observed presentation of this node.
  - target: Loss of the Amniotic Fluid Barrier
    causal_link_type: DIRECT
  - target: Onset of Preterm Parturition
    causal_link_type: DIRECT
- name: Loss of the Amniotic Fluid Barrier
  biological_scale: ORGANISM
  description: >-
    Amniotic fluid drains and the amniotic cavity is continuous with the vagina. Two
    separate harms follow and they scale with different things: fluid volume loss harms
    the fetus in proportion to how early it happens and how long it lasts, whereas the
    open conduit harms in proportion to latency alone.
  locations:
  - preferred_term: amniotic fluid
    term:
      id: UBERON:0000173
      label: amniotic fluid
  - preferred_term: uterine cervix
    term:
      id: UBERON:0000002
      label: uterine cervix
  downstream:
  - target: Oligohydramnios
    causal_link_type: DIRECT
  - target: Ascending Intraamniotic Infection After Rupture
    causal_link_type: DIRECT
- name: Ascending Intraamniotic Infection After Rupture
  biological_scale: ORGANISM
  description: >-
    Colonisation of the now-open amniotic cavity. This is a separate node from the
    ascending colonisation that may have caused the rupture, and confusing the two is
    the standard trap in reading the PPROM literature: an organism recovered after
    rupture may have arrived because of it. The node is retained because it is what
    latency antibiotics are given against and what limits how long expectant management
    can run.
  cell_types:
  - preferred_term: neutrophil
    term:
      id: CL:0000775
      label: neutrophil
  biological_processes:
  - preferred_term: leukocyte migration
    modifier: INCREASED
    term:
      id: GO:0050900
      label: leukocyte migration
  locations:
  - preferred_term: amniotic fluid
    term:
      id: UBERON:0000173
      label: amniotic fluid
  downstream:
  - target: Neonatal sepsis
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
  - target: Onset of Preterm Parturition
    causal_link_type: DIRECT
- name: Onset of Preterm Parturition
  biological_scale: ORGANISM
  description: >-
    Delivery before 37 weeks, whether by spontaneous labour or by the obstetric decision
    the rupture forces. It is modelled as a node rather than only as an outcome because
    three different upstream states reach it - the inflammation that caused the rupture,
    the infection that followed it, and the barrier failure itself - and the management
    question is which of them is driving a given pregnancy.
  biological_processes:
  - preferred_term: parturition
    term:
      id: GO:0007567
      label: parturition
  evidence:
  - reference: PMID:32785751
    reference_title: Novel pathways of inflammation in human fetal membranes associated with preterm birth and preterm pre-labor rupture of the membranes.
    supports: SUPPORT
    quote_role: REVIEW_SYNTHESIS
    evidence_source: OTHER
    snippet: "Inflammatory mediators from damaged membranes are propagated via extracellular vesicles (EV) to maternal uterine tissues and transition quiescent maternal uterine tissues into an active state of labor."
    explanation: >-
      The proposed signalling route from the damaged membrane to myometrial activation,
      which is the mechanism behind the inflammation-to-parturition edges in this entry.
      OTHER is kept on purpose: the vesicle-propagation claim is assembled from cell
      culture and from murine vesicle-transfer experiments, and the review does not say
      which supports which clause of this sentence, so naming a single evidence type
      would assert more than the source does. REVIEW_SYNTHESIS records the provenance.
  downstream:
  - target: Premature birth
    causal_link_type: DIRECT
phenotypes:
- category: Obstetric
  name: Preterm premature rupture of membranes
  description: >-
    Rupture of the chorioamniotic membranes before the onset of labour and before 37
    completed weeks - the defining clinical finding, usually reported as a gush or
    continuous leakage of fluid and confirmed by sterile speculum examination.
  phenotype_term:
    preferred_term: Preterm premature rupture of membranes
    term:
      id: HP:6000310
      label: Preterm premature rupture of membranes
  evidence:
  - reference: PMID:28807394
    reference_title: "Preterm prelabor rupture of the membranes: A disease of the fetal membranes."
    supports: SUPPORT
    quote_role: REVIEW_SYNTHESIS
    evidence_source: HUMAN_CLINICAL
    snippet: "Preterm prelabor rupture of the membranes (pPROM) remains a significant obstetric problem that affects 3-4% of all pregnancies and precedes 40-50% of all preterm births."
    explanation: >-
      Establishes the finding as the entity itself and gives its frequency. Graded as the
      prevalence item that quotes the same sentence: human epidemiology, collated by a
      review rather than measured in it.
- category: Obstetric
  name: Oligohydramnios
  description: >-
    Reduced amniotic fluid volume following the loss of the barrier. Its importance is
    not the measurement but its duration: severe oligohydramnios sustained beyond two
    weeks at an early gestation is what converts a fluid problem into a lethal one.
  phenotype_term:
    preferred_term: Oligohydramnios
    term:
      id: HP:0001562
      label: Oligohydramnios
  evidence:
  - reference: PMID:8828433
    reference_title: "Defining limits of survival: lethal pulmonary hypoplasia after midtrimester premature rupture of membranes."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Neonatal mortality and pulmonary hypoplasia were statistically predicted by gestational age at rupture of membranes and interaction of premature rupture of membranes of > 14 days' duration with severe oligohydramnios."
    explanation: >-
      Identifies the interaction - duration crossed with severity - rather than
      oligohydramnios alone as the predictor, which is what the description records.
  sequelae:
  - target: Pulmonary hypoplasia
    causal_link_type: DIRECT
- category: Neonatal
  name: Pulmonary hypoplasia
  description: >-
    Failure of fetal lung growth when amniotic fluid is absent during the canalicular
    phase of development. It is the harm that makes previable PPROM categorically
    different from later PPROM, and the one that is not fixed by delivering the fetus.
  phenotype_term:
    preferred_term: Pulmonary hypoplasia
    term:
      id: HP:0002089
      label: Pulmonary hypoplasia
  subtype: Previable
  evidence:
  - reference: PMID:8828433
    reference_title: "Defining limits of survival: lethal pulmonary hypoplasia after midtrimester premature rupture of membranes."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Severe oligohydramnios > 14 days after premature rupture of membranes at < 25 weeks' gestation has a predicted neonatal mortality of > 90%."
    explanation: >-
      The mortality figure attached to the gestational-age and duration thresholds that
      define the previable subtype.
- category: Obstetric
  name: Premature birth
  description: >-
    Delivery before 37 completed weeks. In PPROM this is the outcome that carries almost
    all of the harm, which is why the whole therapeutic repertoire is organised around
    deferring it safely rather than preventing the rupture.
  phenotype_term:
    preferred_term: Premature birth
    term:
      id: HP:0001622
      label: Premature birth
  evidence:
  - reference: PMID:11293640
    reference_title: "Broad-spectrum antibiotics for preterm, prelabour rupture of fetal membranes: the ORACLE I randomised trial. ORACLE Collaborative Group."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Preterm, prelabour rupture of the fetal membranes (pPROM) is the commonest antecedent of preterm birth, and can lead to death, neonatal disease, and long-term disability."
    explanation: States the relationship between the entity and this phenotype directly.
  sequelae:
  - target: Neonatal respiratory distress
    causal_link_type: DIRECT
- category: Neonatal
  name: Neonatal respiratory distress
  description: >-
    Respiratory distress syndrome of prematurity, from surfactant insufficiency in an
    immature lung. It is the neonatal outcome that both antenatal corticosteroids and
    latency antibiotics were shown to reduce, and the one the PPROMT trial found was
    increased by delivering late-preterm PPROM immediately.
  phenotype_term:
    preferred_term: Neonatal respiratory distress
    term:
      id: HP:0002643
      label: Neonatal respiratory distress
  evidence:
  - reference: PMID:26564381
    reference_title: "Immediate delivery compared with expectant management after preterm pre-labour rupture of the membranes close to term (PPROMT trial): a randomised controlled trial."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "neonates born to mothers in the immediate delivery group had increased rates of respiratory distress (76 [8%] of 919 vs 47 [5%] of 910, RR 1·6, 95% CI 1·1-2·30; p=0·008)"
    explanation: >-
      Quantifies the phenotype as the cost of immediate delivery in the late-preterm
      window, which is the trade-off this entry's treatment section is built around.
- category: Neonatal
  name: Neonatal sepsis
  description: >-
    Bloodstream infection in the newborn following exposure to an infected amniotic
    cavity. This is the harm that expectant management is weighed against, and the
    PPROMT trial's primary outcome.
  phenotype_term:
    preferred_term: Neonatal sepsis
    term:
      id: HP:0040187
      label: Neonatal sepsis
  evidence:
  - reference: PMID:26564381
    reference_title: "Immediate delivery compared with expectant management after preterm pre-labour rupture of the membranes close to term (PPROMT trial): a randomised controlled trial."
    supports: REFUTE
    evidence_source: HUMAN_CLINICAL
    snippet: "Neonatal sepsis occurred in 23 (2%) of 923 neonates whose mothers were assigned to immediate birth and 29 (3%) of 912 neonates of mothers assigned to expectant management (relative risk [RR] 0·8, 95% CI 0·5-1·3; p=0·37)."
    explanation: >-
      Recorded as REFUTE against the specific claim that waiting after late-preterm PPROM
      raises neonatal sepsis: the trial was powered for exactly that outcome and did not
      find it. It does not refute neonatal sepsis as a phenotype of the disease, which
      the same trial reports in both arms.
histopathology:
- name: Acute Histologic Chorioamnionitis and Funisitis
  description: >-
    The pathological correlate of the inflammation nodes, read on the delivered placenta
    and membranes: neutrophilic infiltration of the choriodecidua, the amnion, the
    chorionic plate and - when the fetus has mounted its own response - the umbilical
    cord. What makes the lesion worth recording separately in PPROM rather than folding
    into the generic chorioamnionitis picture is its distribution. In preterm labour with
    intact membranes, membranes without demonstrable intraamniotic inflammation show
    inflammation in the choriodecidua only; in PPROM the same inflammation-negative group
    already has inflammation in every compartment, including the fetal ones. That is a
    direct histological argument for this entry's structure, in which the breached
    barrier and the inflammation are separate nodes and the barrier failure can precede
    the measurable intraamniotic response rather than follow it.
  diagnostic: false
  finding_term:
    preferred_term: Acute histologic chorioamnionitis
    term:
      id: NCIT:C111944
      label: Histologic Chorioamnionitis
  notes: >-
    Only the chorioamnionitis component is bindable. NCIT:C97077 Funisitis sits under
    NCIT:C2991 Disease or Disorder rather than under NCIT:C83490 Histopathology Result,
    so it is not reachable from the HistopathologyFindingTerm enum roots and cannot be
    bound in this slot; the same upstream placement gap is recorded on the
    Chorioamnionitis entry. The quoted compartment frequencies below contain the source's
    own typographical error ("all-compartment0s"), which is reproduced verbatim because a
    snippet never corrects the source it quotes.
  evidence:
  - reference: PMID:27090052
    reference_title: "Preterm labor and preterm premature rupture of membranes have a different pattern in the involved compartments of acute histologoic chorioamnionitis and/or funisitis: Patho-physiologic implication related to different clinical manifestations."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "inflammation appeared in all-compartment0s (choriodeciduitis-46.2 %; amnionitis-23.1 %; funisitis-30.8 %; chorionic-plate inflammation-7.7 %) in IAI(-)/FIRS(-) group with preterm-PROM"
    explanation: >-
      Gives the compartment-by-compartment frequencies in the PPROM cases that had no
      measurable intraamniotic inflammation, which is the observation that separates this
      lesion's distribution in PPROM from its distribution in preterm labour.
  - reference: PMID:27090052
    reference_title: "Preterm labor and preterm premature rupture of membranes have a different pattern in the involved compartments of acute histologoic chorioamnionitis and/or funisitis: Patho-physiologic implication related to different clinical manifestations."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "We first demonstrated that PTL and preterm-PROM had a different pattern in the involved compartments of acute-HCA and/or funisitis"
    explanation: >-
      States the study's own conclusion, which is the reason this finding is curated on
      the PPROM entry rather than left to the Chorioamnionitis entry.
biochemical:
- name: Amniotic Fluid Interleukin-6
  presence: INCREASED
  notes: >-
    The operational definition of intraamniotic inflammation after PPROM, and the reason
    the inflammation node in this entry is separable from the colonisation node above it:
    IL-6 defines the inflammatory state whether or not an organism is recoverable. The
    cited study used an ELISA threshold of 2600 pg/mL to define intraamniotic
    inflammation and a 745 pg/mL cut-off for the bedside test; those numbers are recorded
    here as context rather than as quoted evidence, because the sentence carrying them in
    the cached full text is set with typographic thin spaces that no verbatim snippet
    could reproduce safely.
  readouts:
  - target: Intraamniotic Inflammatory Response
    relationship: READOUT_OF
    direction: POSITIVE
    endpoint_context: DIAGNOSTIC
    interpretation: >-
      A raised amniotic fluid IL-6 concentration is what the node is measured by in
      practice; it is a readout of the inflammation, not a cause of it.
    evidence:
    - reference: PMID:25758620
      reference_title: "A point of care test for interleukin-6 in amniotic fluid in preterm prelabor rupture of membranes: a step toward the early treatment of acute intra-amniotic inflammation/infection."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "A POC AF IL-6 test can identify intra-amniotic inflammation in patients with preterm PROM."
      explanation: >-
        States that the marker identifies the node's state in this disease, which is the
        readout claim this link makes.
  evidence:
  - reference: PMID:25758620
    reference_title: "A point of care test for interleukin-6 in amniotic fluid in preterm prelabor rupture of membranes: a step toward the early treatment of acute intra-amniotic inflammation/infection."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The POC test for AF IL-6 concentrations had 97% sensitivity and 96% specificity for the identification of intra-amniotic inflammation"
    explanation: >-
      Quantifies the bedside assay against the laboratory standard in a PPROM cohort,
      which is what makes the marker usable at the time the diagnosis is made.
- name: Amniotic Fluid Matrix Metalloproteinase-8
  presence: INCREASED
  notes: >-
    Neutrophil collagenase in the amniotic fluid, which in this entry is both a marker of
    the intraamniotic inflammatory response and a member of the enzyme family that
    degrades the collagen holding the amniochorion together - the same MMP activity the
    collagen-degradation node models. Its intensity is steeply gestational-age dependent:
    the earlier the rupture, the higher the concentration.
  readouts:
  - target: Intraamniotic Inflammatory Response
    relationship: READOUT_OF
    direction: POSITIVE
    endpoint_context: DIAGNOSTIC
    interpretation: >-
      Amniotic fluid MMP-8 above a threshold is the criterion used to call intraamniotic
      inflammation present in the histopathology study curated above, so it operationalises
      the same node IL-6 does.
    evidence:
    - reference: PMID:27090052
      reference_title: "Preterm labor and preterm premature rupture of membranes have a different pattern in the involved compartments of acute histologoic chorioamnionitis and/or funisitis: Patho-physiologic implication related to different clinical manifestations."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "IAI (amniotic-fluid MMP-8 ≥ 23 ng/ml)"
      explanation: >-
        The threshold at which this cohort called intraamniotic inflammation present,
        quoted from the study that used it to stratify the placental findings.
  evidence:
  - reference: PMID:31141489
    reference_title: The earlier the gestational age, the greater the intensity of the intra-amniotic inflammatory response in women with preterm premature rupture of membranes and amniotic fluid infection by Ureaplasma species.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The median values of amniotic fluid MMP-8 concentration and WBC count were the highest in the extreme preterm PROM group and the lowest in the late preterm PROM group"
    explanation: >-
      Establishes the gestational-age gradient in the marker, which is the observation
      that makes the earliest ruptures the most inflamed rather than merely the most
      premature. Measured in a cohort restricted to Ureaplasma-positive amniotic fluid,
      so the gradient is demonstrated within one organism class rather than across all
      PPROM.
genetic:
- name: SERPINH1
  gene_term:
    preferred_term: SERPINH1
    term:
      id: hgnc:1546
      label: SERPINH1
  association: Promoter variant reducing HSP47 expression; susceptibility allele enriched in African ancestry
  relationship_type: SUSCEPTIBILITY
  notes: >
    SERPINH1 encodes HSP47, the collagen-specific molecular chaperone. The -656 C>T
    promoter variant reduces transcription in amnion fibroblasts and is associated with
    PPROM in African Americans, with the association surviving adjustment for genetic
    ancestry using 29 ancestry-informative markers - which is the step that makes it a
    variant effect rather than a population-stratification artefact. A separate 12-bp
    deletion in the same 5'-flanking region runs the other way and is protective
    (PMID:18205191, carried as a top-level reference rather than as an evidence item:
    it is a Mutation in Brief with no abstract indexed, so the only quotable text is its
    title, and a title is not a finding). Note
    that this is a susceptibility allele in a multifactorial condition and not a
    Mendelian cause; MONDO nonetheless classifies MONDO:0012511 under hereditary
    disease, which this entry does not follow.
  evidence:
  - reference: PMID:16938879
    reference_title: A functional SNP in the promoter of the SERPINH1 gene increases risk of preterm premature rupture of membranes in African Americans.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "An initial case-control study demonstrated that the -656 T allele is significantly more frequent in African-American neonates (P < 0.0009) born from pregnancies complicated by PPROM compared with controls (odds ratio of 3.22, 95% confidence interval 1.50, 7.22)."
    explanation: The clinical association with its effect size, from the discovery case-control study.
  - reference: PMID:16938879
    reference_title: A functional SNP in the promoter of the SERPINH1 gene increases risk of preterm premature rupture of membranes in African Americans.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "There was no significant difference in ancestry among cases and controls using a dihybrid model based on 29 ancestry-informative markers."
    explanation: >-
      The admixture control. Without it the association in an ancestry-enriched allele
      would be uninterpretable, so it is cited separately rather than folded into the
      effect-size item.
  - reference: PMID:16938879
    reference_title: A functional SNP in the promoter of the SERPINH1 gene increases risk of preterm premature rupture of membranes in African Americans.
    supports: SUPPORT
    quote_role: BACKGROUND
    evidence_source: IN_VITRO
    snippet: "SERPINH1 encodes heat-shock protein 47, a chaperone essential for collagen synthesis."
    explanation: >-
      The gene's function, which is what connects the variant to the collagen-synthesis
      node. Tagged BACKGROUND because it is established biochemistry restated in the
      paper's introduction rather than the paper's own result; graded IN_VITRO because
      the chaperone function it restates was established in cell and biochemical systems,
      not in the case-control cohort this paper reports.
environmental:
- name: Maternal Cigarette Smoking
  description: >-
    Heavy smoking raises PPROM risk, and the effect is largest at the earliest
    gestations - roughly fivefold before 28 weeks against twofold before 37. The
    gestational gradient is what makes this more than an epidemiological association
    here: it is consistent with an exposure acting on a membrane that has to survive
    longer, and the same oxidant exposure reproduces the PPROM senescence phenotype in
    term membranes in vitro.
  exposure_term:
    preferred_term: exposure to cigarette smoking via maternal
    term:
      id: ECTO:0300003
      label: exposure to cigarette smoking via maternal
  influences_mechanisms:
  - target: Oxidative Stress in the Fetal Membranes
    environmental_effect: PREDISPOSES
    causal_link_type: INDIRECT_KNOWN_INTERMEDIATES
    description: >-
      The intermediate is named and has been tested: cigarette smoke extract applied to
      term fetal membranes raises phospho-p38 MAPK and produces the organelle changes of
      the senescence phenotype. The human data give the risk; the in vitro data give the
      step.
    evidence:
    - reference: PMID:24832021
      reference_title: Histological evidence of oxidative stress and premature senescence in preterm premature rupture of the human fetal membranes recapitulated in vitro.
      supports: SUPPORT
      directness: DIRECT
      evidence_source: IN_VITRO
      snippet: "In vitro cigarette smoke extract exposure increased p-p38 MAPK without any detectable change in p-p53 MAPK."
      explanation: >-
        The measured effect of the exposure on the oxidative-stress and senescence
        signalling this node models. Quoted with the negative result for p-p53 intact.
  evidence:
  - reference: PMID:23329562
    reference_title: Increased risk of preterm premature rupture of membranes at early gestational ages among maternal cigarette smokers.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "smoking > 10 cigarettes per day was associated with an increased risk of PPROM at < 28 weeks (odds ratio [OR] 5.28; 95% confidence interval [CI] 2.20 to 12.7)"
    explanation: >-
      The largest effect in the series, from a 17,961-birth retrospective cohort; the
      same sentence carries the smaller estimates at later gestational ages.
  - reference: PMID:23329562
    reference_title: Increased risk of preterm premature rupture of membranes at early gestational ages among maternal cigarette smokers.
    supports: NO_EVIDENCE
    evidence_source: HUMAN_CLINICAL
    snippet: "Smoking 1 to 10 cigarettes per day was not associated with a significant risk of PPROM at any gestational age."
    explanation: >-
      Recorded as NO_EVIDENCE against any claim that light smoking carries this risk.
      The exposure is dose-dependent and the entry should not be readable as attributing
      risk to smoking at any level.
diagnosis:
- name: Sterile Speculum Examination
  description: >-
    Direct visualisation of amniotic fluid pooling in the posterior vaginal fornix, or
    of fluid escaping the cervical os, through a speculum passed without digital
    examination. It is the reference standard and it is also the act that defines the
    disease clinically: everything else on this list exists for the cases where the
    speculum finding is equivocal. Digital examination is avoided because it shortens
    latency and introduces organisms into a cavity that is already open.
  diagnosis_term:
    preferred_term: sterile speculum examination
    term:
      id: NCIT:C38104
      label: Pelvic Examination
  presence: Positive
  results: Visible pooling of amniotic fluid in the posterior fornix or fluid egressing from the cervical os
  notes: >-
    NCIT has no clinical-action term for speculum examination specifically. NCIT:C17614
    Colposcope and NCIT:C88208 Culdoscope name instruments rather than actions and are
    not reachable from NCIT:C25218; NCIT:C127946 GAIA Level 3 Assessment of Premature
    Preterm Rupture of Membranes describes this exact finding in its definition but is a
    case-definition assessment rather than a clinical action. NCIT:C38104 Pelvic
    Examination is the most specific reachable action term, with the specificity carried
    in preferred_term.
  evidence:
  - reference: PMID:41468127
    reference_title: Laboratory Tests for the Diagnosis of Rupture of Membranes.
    supports: SUPPORT
    quote_role: REVIEW_SYNTHESIS
    evidence_source: HUMAN_CLINICAL
    snippet: "The gold standard for diagnosis is visualizing clear, amniotic fluid egressing from the external cervical os or with an amniocentesis dye test."
    explanation: >-
      Names the reference standard this record encodes, and the invasive alternative that
      the amniocentesis record below covers.
- name: Nitrazine and Ferning Tests
  description: >-
    The two bedside adjuncts read off the same speculum swab: nitrazine paper turning
    blue on the alkaline pH of amniotic fluid against the acid pH of the normal vagina,
    and an arborising crystal pattern when a dried smear is examined under the
    microscope. Together with the examination itself they settle the large majority of
    presentations. Both are falsifiable by the things that also raise vaginal pH - blood,
    semen, bacterial vaginosis - which is why they are adjuncts and not the standard.
  diagnosis_term:
    preferred_term: nitrazine and fern testing of vaginal fluid
    term:
      id: NCIT:C25294
      label: Laboratory Procedure
  markers: Vaginal fluid pH; arborisation (ferning) of a dried vaginal fluid smear
  evidence:
  - reference: PMID:41468127
    reference_title: Laboratory Tests for the Diagnosis of Rupture of Membranes.
    supports: SUPPORT
    quote_role: REVIEW_SYNTHESIS
    evidence_source: HUMAN_CLINICAL
    snippet: "Greater than 90% of rupture of membrane diagnoses can be made with physical examination, nitrazine testing, and microscopic fern testing."
    explanation: >-
      Quantifies how much of the diagnostic work this record and the speculum record do
      between them, which is what bounds the role of the immunoassays below.
  - reference: PMID:27855117
    reference_title: Comparison of the duo of insulin-like growth factor binding protein-1/alpha fetoprotein (Amnioquick duo+®) and traditional clinical assessment for diagnosing premature rupture of fetal membranes.
    supports: SUPPORT
    directness: DIRECT
    evidence_source: HUMAN_CLINICAL
    snippet: "The specificity and sensitivity values for TCA were 76.2% and 85.2%"
    explanation: >-
      Gives the measured performance of nitrazine, ferning and pooling taken together
      against a post-delivery reference standard, which is the number that makes the case
      for an immunoassay in equivocal presentations.
- name: Amniotic Fluid Protein Immunoassay
  description: >-
    Bedside immunochromatographic detection of a protein that is abundant in amniotic
    fluid and scarce in normal cervicovaginal secretions - placental alpha-microglobulin-1
    (PAMG-1) or insulin-like growth factor binding protein-1 (IGFBP-1), alone or paired
    with alpha-fetoprotein. Their place is the equivocal presentation, not the routine
    one: where the speculum finding is unambiguous they add nothing, and where it is
    absent they are what prevents either an unnecessary admission or a missed rupture.
  diagnosis_term:
    preferred_term: cervicovaginal PAMG-1 or IGFBP-1 immunoassay
    term:
      id: NCIT:C25294
      label: Laboratory Procedure
  markers: Placental alpha-microglobulin-1 (PAMG-1); insulin-like growth factor binding protein-1 (IGFBP-1)
  results: Accuracy 98.7% (IGFBP-1) and 93.9% (PAMG-1) against clinical follow-up in PPROM at 20-36 weeks
  evidence:
  - reference: PMID:31099162
    reference_title: Comparative analysis of Insulin-like growth factor binding protein-1, placental alpha-microglobulin-1, phenol and pH for the diagnosis of preterm premature rupture of membranes between 20 and 36 weeks.
    supports: SUPPORT
    directness: DIRECT
    evidence_source: HUMAN_CLINICAL
    snippet: "Similar accuracies were observed for IGFBP-1 (98.7%) and PAMG-1 (93.9%)."
    explanation: >-
      Head-to-head accuracy of the two marker proteins in exactly this entry's
      gestational window, which is why the record names both rather than preferring one.
  - reference: PMID:31099162
    reference_title: Comparative analysis of Insulin-like growth factor binding protein-1, placental alpha-microglobulin-1, phenol and pH for the diagnosis of preterm premature rupture of membranes between 20 and 36 weeks.
    supports: REFUTE
    evidence_source: HUMAN_CLINICAL
    snippet: "there is no significant difference between PAMG-1 and traditional tests"
    explanation: >-
      Recorded as REFUTE against the claim that an immunoassay is generally superior to
      the bedside tests. The same study that gives the accuracy figures above declines to
      separate PAMG-1 from traditional assessment, and concludes the tests should be used
      sparingly where they are expensive.
  - reference: PMID:41468127
    reference_title: Laboratory Tests for the Diagnosis of Rupture of Membranes.
    supports: SUPPORT
    quote_role: REVIEW_SYNTHESIS
    evidence_source: HUMAN_CLINICAL
    snippet: "Commercial immunoassays should be utilized in equivocal cases to assist in the diagnosis of membrane rupture when the diagnosis is unclear."
    explanation: >-
      Places the immunoassays in the equivocal case rather than in the routine one, which
      is the scoping claim this record makes.
- name: Obstetric Ultrasound for Amniotic Fluid Volume
  description: >-
    Sonographic assessment of residual amniotic fluid. It cannot diagnose the rupture -
    oligohydramnios has other causes and a recently ruptured sac may still measure
    normally - but it is what converts a suspected rupture into a confirmed one over the
    following days, and the residual volume and its persistence are what govern the
    previable subtype's counselling, since it is prolonged anhydramnios rather than the
    rupture that produces pulmonary hypoplasia.
  diagnosis_term:
    preferred_term: obstetric ultrasonography for amniotic fluid volume
    term:
      id: NCIT:C17230
      label: Ultrasound Imaging
  results: Reduced or absent amniotic fluid; persistence over serial scans supports the diagnosis
  evidence:
  - reference: PMID:31099162
    reference_title: Comparative analysis of Insulin-like growth factor binding protein-1, placental alpha-microglobulin-1, phenol and pH for the diagnosis of preterm premature rupture of membranes between 20 and 36 weeks.
    supports: SUPPORT
    directness: INDIRECT
    evidence_source: HUMAN_CLINICAL
    snippet: "a diagnosis of PROM was confirmed by a definitive evolution of the clinical symptoms (visualization of vaginal amniotic fluid or persistence of oligohydramnios)"
    explanation: >-
      INDIRECT because the study describes persisting oligohydramnios as one half of its
      reference standard rather than measuring ultrasound as an index test. That is
      exactly the role recorded here - a confirmatory observation over time, not a
      diagnostic test at presentation.
- name: Amniocentesis for Intraamniotic Inflammation and Infection
  description: >-
    Transabdominal sampling of amniotic fluid, tested in parallel for organisms and for
    inflammation. It does not diagnose the rupture; it answers the separate question this
    entry keeps as a separate node - whether the cavity is inflamed, and whether an
    organism is recoverable - which is what the expectant-management decision turns on.
    It is invasive, is not used routinely, and after rupture it is often technically
    limited by the loss of fluid it is trying to sample.
  diagnosis_term:
    preferred_term: amniocentesis for amniotic fluid culture and inflammatory markers
    term:
      id: NCIT:C52009
      label: Amniocentesis
  markers: Amniotic fluid interleukin-6; matrix metalloproteinase-8; white blood cell count; Gram stain and culture
  evidence:
  - reference: PMID:25758620
    reference_title: "A point of care test for interleukin-6 in amniotic fluid in preterm prelabor rupture of membranes: a step toward the early treatment of acute intra-amniotic inflammation/infection."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Amniocentesis was performed at the time of diagnosis, and AF was analyzed using cultivation techniques for aerobic and anaerobic bacteria as well as genital mycoplasmas."
    explanation: >-
      Describes the procedure and the parallel microbiological testing in a PPROM cohort,
      which is the practice this record models and the source of the biomarkers curated
      in the biochemical section.
treatments:
- name: Latency Antibiotics
  description: >-
    A course of antibiotics given after PPROM to prolong the interval to delivery and to
    reduce neonatal infection and its consequences. Two large randomised trials define
    it and they do not agree on regimen: the NICHD trial used intravenous ampicillin
    plus erythromycin followed by oral amoxicillin plus erythromycin, while ORACLE I
    found the benefit in erythromycin alone and found that co-amoxiclav raised neonatal
    necrotising enterocolitis. Contemporary practice follows the safety finding rather
    than the efficacy finding, which is why the amoxicillin component is recorded here
    with that caveat attached rather than as an equal option.
  therapeutic_modality: SMALL_MOLECULE
  treatment_term:
    preferred_term: Pharmacotherapy
    term:
      id: NCIT:C15986
      label: Pharmacotherapy
    therapeutic_agent:
    - preferred_term: erythromycin
      term:
        id: CHEBI:48923
        label: erythromycin
    - preferred_term: ampicillin
      term:
        id: CHEBI:28971
        label: ampicillin
    - preferred_term: amoxicillin
      term:
        id: CHEBI:2676
        label: amoxicillin
  target_mechanisms:
  - target: Ascending Intraamniotic Infection After Rupture
    description: >-
      The intended target is the infection that follows the breach, not the mechanism
      that caused it. That is the honest reading of these trials: they buy latency and
      reduce neonatal infection, and neither one shows that treating infection prevents
      rupture.
    evidence:
    - reference: PMID:32591087
      reference_title: Antibiotic administration reduces the rate of intraamniotic inflammation in preterm prelabor rupture of the membranes.
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "Intravenous therapy with clarithromycin was associated with a reduction in the intensity of the intraamniotic inflammatory response in patients with PPROM with either intraamniotic infection or sterile intraamniotic inflammation."
      explanation: >-
        Direct evidence that antibiotic therapy moves the intraamniotic inflammation this
        edge targets, measured by paired amniocentesis rather than by outcome alone. The
        agent is clarithromycin, which is not the regimen recorded above.
  evidence:
  - reference: PMID:9307346
    reference_title: Antibiotic therapy for reduction of infant morbidity after preterm premature rupture of the membranes. A randomized controlled trial. National Institute of Child Health and Human Development Maternal-Fetal Medicine Units Network.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "In the total study population, the primary outcome (44.1 % vs 52.9%; P=.04), respiratory distress (40.5% vs 48.7%; P=.04), and necrotizing enterocolitis (2.3% vs 5.8%; P=.03) were less frequent with antibiotics."
    explanation: The NICHD trial's primary result, in the 24-32 week window.
  - reference: PMID:11293640
    reference_title: "Broad-spectrum antibiotics for preterm, prelabour rupture of fetal membranes: the ORACLE I randomised trial. ORACLE Collaborative Group."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Among the 2260 singletons in this comparison, significantly fewer had the composite primary outcome in the erythromycin group (125 of 1111 [11.2%] vs 166 of 1149 [14.4%], p=0.02)."
    explanation: >-
      ORACLE I's erythromycin result in singletons. Note the same comparison across all
      infants did not reach significance, which the trial reports separately.
  - reference: PMID:11293640
    reference_title: "Broad-spectrum antibiotics for preterm, prelabour rupture of fetal membranes: the ORACLE I randomised trial. ORACLE Collaborative Group."
    supports: REFUTE
    evidence_source: HUMAN_CLINICAL
    snippet: "Although co-amoxiclav only and co-amoxiclav plus erythromycin were associated with prolongation of pregnancy, they were also associated with a significantly higher rate of neonatal necrotising enterocolitis."
    explanation: >-
      REFUTE against the claim that co-amoxiclav is an acceptable latency regimen. It
      does not refute latency antibiotics generally - the same trial supports
      erythromycin - which is why it is a separate item rather than a qualifier on the
      one above.
- name: Antenatal Corticosteroids
  description: >-
    A single course of betamethasone or dexamethasone given when preterm delivery is
    anticipated, to accelerate fetal lung maturation. It is the intervention with the
    largest and most certain effect on the outcome that carries most of the harm in
    PPROM, and the concern specific to this population - that a steroid in a pregnancy
    with ruptured membranes raises maternal infection - is addressed by the same
    systematic review, which finds little to no difference in chorioamnionitis with wide
    confidence intervals.
  therapeutic_modality: SMALL_MOLECULE
  treatment_term:
    preferred_term: Pharmacotherapy
    term:
      id: NCIT:C15986
      label: Pharmacotherapy
    therapeutic_agent:
    - preferred_term: betamethasone
      term:
        id: CHEBI:3077
        label: betamethasone
    - preferred_term: dexamethasone
      term:
        id: CHEBI:41879
        label: dexamethasone
  target_mechanisms:
  - target: Neonatal respiratory distress
    description: >-
      The target is the consequence of prematurity, not any node in the membrane-failure
      chain. Nothing in this entry's pathophysiology is altered by corticosteroids, and
      the entry should not be readable as claiming otherwise.
  evidence:
  - reference: PMID:33368142
    reference_title: Antenatal corticosteroids for accelerating fetal lung maturation for women at risk of preterm birth.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "respiratory distress syndrome (RR 0.71, 95% CI 0.65 to 0.78; 11,183 infants; studies = 26; high-certainty evidence; 4.3% fewer, 95% CI 3.2% to 5.2% fewer)"
    explanation: The pooled effect on the outcome this treatment targets, graded high certainty.
  - reference: PMID:33368142
    reference_title: Antenatal corticosteroids for accelerating fetal lung maturation for women at risk of preterm birth.
    supports: NO_EVIDENCE
    evidence_source: HUMAN_CLINICAL
    snippet: "The wide 95% CIs in all of these outcomes include possible benefit and possible harm."
    explanation: >-
      Recorded as NO_EVIDENCE against the maternal-infection concern in either direction.
      The review's own reading of its maternal outcomes, including chorioamnionitis, is
      that they are imprecise - which is a different statement from safety.
- name: Magnesium Sulphate for Fetal Neuroprotection
  description: >-
    Magnesium sulphate given to a woman at risk of delivering before 34 weeks, to reduce
    cerebral palsy in the child. Like corticosteroids it treats the consequence of
    preterm birth rather than the membrane disease, and it is included because PPROM is
    one of the commonest routes into the population in which it is indicated.
  therapeutic_modality: SMALL_MOLECULE
  treatment_term:
    preferred_term: Pharmacotherapy
    term:
      id: NCIT:C15986
      label: Pharmacotherapy
    therapeutic_agent:
    - preferred_term: magnesium sulfate
      term:
        id: CHEBI:32599
        label: magnesium sulfate
  target_mechanisms:
  - target: Premature birth
    description: >-
      The edge means addresses a consequence of, not prevents. Magnesium sulphate given
      for neuroprotection does not prolong the pregnancy and is not a tocolytic in this
      indication - the cited review explicitly excludes trials using it for tocolysis.
  evidence:
  - reference: PMID:38726883
    reference_title: Magnesium sulphate for women at risk of preterm birth for neuroprotection of the fetus.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "magnesium sulphate compared with placebo reduced cerebral palsy (RR 0.71, 95% CI 0.57 to 0.89; 6 RCTs, 6107 children; number needed to treat for additional beneficial outcome (NNTB) 60, 95% CI 41 to 158)"
    explanation: The pooled effect on cerebral palsy with its number needed to treat, graded high certainty.
  - reference: PMID:38726883
    reference_title: Magnesium sulphate for women at risk of preterm birth for neuroprotection of the fetus.
    supports: NO_EVIDENCE
    evidence_source: HUMAN_CLINICAL
    snippet: "We did not include studies where magnesium sulphate was used with the primary aim of preterm labour tocolysis, or the prevention and/or treatment of eclampsia."
    explanation: >-
      Recorded as NO_EVIDENCE against reading this treatment as prolonging the pregnancy.
      The review's exclusion criterion is what makes the neuroprotective indication a
      separate claim from tocolysis.
- name: Expectant Management with Surveillance
  description: >-
    Deferring delivery while watching for infection and fetal compromise. It is the
    default below 34 weeks and, since the PPROMT trial, also the default between 34 and
    37 weeks in the absence of overt infection - a reversal of the previous assumption
    that the infection risk of waiting outweighed the prematurity risk of delivering. The
    trial found no reduction in neonatal sepsis from immediate birth and more respiratory
    distress, more ventilation and longer intensive care; it also found the trade is not
    free on the maternal side, with more antepartum or intrapartum haemorrhage and
    intrapartum fever in the expectant arm, against fewer caesareans.
  therapeutic_modality: BEHAVIORAL
  treatment_term:
    preferred_term: expectant management with maternal and fetal surveillance
    term:
      id: NCIT:C49236
      label: Therapeutic Procedure
  target_mechanisms:
  - target: Onset of Preterm Parturition
    description: >-
      What is being managed is the timing of delivery, which is the node this edge
      points at. The intervention is a decision not to intervene, so nothing in the
      membrane-failure chain upstream of it is touched.
  evidence:
  - reference: PMID:26564381
    reference_title: "Immediate delivery compared with expectant management after preterm pre-labour rupture of the membranes close to term (PPROMT trial): a randomised controlled trial."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "In the absence of overt signs of infection or fetal compromise, a policy of expectant management with appropriate surveillance of maternal and fetal wellbeing should be followed in pregnant women who present with ruptured membranes close to term."
    explanation: >-
      The trial's own interpretation, which is the recommendation this treatment records,
      with its two explicit preconditions.
  - reference: PMID:26564381
    reference_title: "Immediate delivery compared with expectant management after preterm pre-labour rupture of the membranes close to term (PPROMT trial): a randomised controlled trial."
    supports: REFUTE
    evidence_source: HUMAN_CLINICAL
    snippet: "those assigned to the expectant management group had higher risks of antepartum or intrapartum haemorrhage (RR 0·6, 95% CI 0·4-0·9), intrapartum fever (0·4, 0·2-0·9), and use of postpartum antibiotics (0·8, 0·7-1·0), and longer hospital stay (p<0·0001), but a lower risk of caesarean delivery (RR 1·4, 95% CI 1·2-1·7)."
    explanation: >-
      REFUTE against any reading of this treatment as costless. The maternal harms sit in
      the same trial that supports the policy, and are cited from it rather than
      elsewhere.
clinical_trials:
- name: ISRCTN44485060
  phase: NOT_APPLICABLE
  status: COMPLETED
  description: >-
    The PPROMT trial - immediate delivery versus expectant management for PPROM between
    34 weeks and 36 weeks and 6 days, with neonatal sepsis as the primary outcome. It
    has no NCT identifier: it is registered on ISRCTN and reached here through the WHO
    ICTRP, which is the identifier the publication itself cites. `phase` follows the
    registry's own Not Applicable value rather than assigning a phase the register does
    not claim.
  target_phenotypes:
  - preferred_term: Neonatal sepsis
    term:
      id: HP:0040187
      label: Neonatal sepsis
  - preferred_term: Neonatal respiratory distress
    term:
      id: HP:0002643
      label: Neonatal respiratory distress
  evidence:
  - reference: ICTRP:ISRCTN44485060
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Current inclusion criteria as of 12/02/2009: Singleton pregnancies, with confirmed ruptured membranes from 34 weeks to 36 weeks and 6 days gestation."
    explanation: >-
      WHO ICTRP registration record establishing the trial's identity and its registered
      eligibility window, which is the window the late-preterm subtype names. OTHER is
      the right grade and no quote_role applies: a registration document is not study
      evidence and has no argument of its own for the quote to sit in.
  - reference: PMID:26564381
    reference_title: "Immediate delivery compared with expectant management after preterm pre-labour rupture of the membranes close to term (PPROMT trial): a randomised controlled trial."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The PPROMT trial was a multicentre randomised controlled trial done at 65 centres across 11 countries."
    explanation: Establishes the trial's design and scale, from the primary report.
discussions:
- discussion_id: gap_pprom_senescence_cause_or_marker
  kind: KNOWLEDGE_GAP
  status: OPEN
  prompt: >-
    Is premature senescence of the amniochorion a cause of PPROM, or a marker of
    membranes that were already destined to fail?
  attaches_to:
  - pathophysiology#Premature Senescence of the Amniochorion
  rationale: >-
    The senescence evidence is strong on association and on inducibility, and those are
    different claims. Membranes from PPROM carry the markers at term-like frequencies,
    and an oxidant exposure produces the same phenotype in term membranes in vitro - but
    no study shows that blocking senescence prevents rupture, and no in vivo experiment
    separates senescence from the oxidative stress that induces it. The distinction is
    not academic: it decides whether senescence is a screening biomarker or a
    therapeutic target, and the field's own reviews call for exactly this work.
  proposed_experiments:
  - experiment_id: exp_pprom_senescence_blockade_mechanical_endpoint
    name: Senescence blockade in a fetal membrane organ-on-chip under oxidant challenge
    description: >-
      Apply an oxidant challenge to a human fetal membrane organ-on-chip with and
      without senolytic or p38 inhibition, and measure both the senescence markers and a
      mechanical endpoint. The mechanical endpoint is the point of the experiment:
      showing that blockade prevents marker accumulation would only repeat what is
      already known.
    would_support:
    - pathophysiology#Premature Senescence of the Amniochorion
    supporting_outcome:
    - >-
      Senescence blockade preserves membrane tensile strength or rupture pressure under
      an oxidant challenge that weakens untreated membranes.
    refuting_outcome:
    - >-
      Senescence markers are suppressed but the membranes weaken to the same degree,
      placing the mechanical failure downstream of oxidative stress but not of
      senescence.
  evidence:
  - reference: PMID:28807394
    reference_title: "Preterm prelabor rupture of the membranes: A disease of the fetal membranes."
    supports: SUPPORT
    quote_role: REVIEW_SYNTHESIS
    evidence_source: OTHER
    snippet: "Further studies on senescence activation and microfracture formation and their role in maintaining membrane homeostasis are needed to fill the knowledge gaps in our understanding of pPROM"
    explanation: >-
      The review states this gap in its own words, which is why it is recorded here
      rather than inferred. OTHER is correct and stays: a statement that evidence is
      missing describes no study. REVIEW_SYNTHESIS marks it as the review's assessment.
- discussion_id: gap_pprom_organism_direction
  kind: KNOWLEDGE_GAP
  status: OPEN
  prompt: >-
    Does an organism recovered from the amniotic cavity after PPROM reflect a cause of
    the rupture or a consequence of it?
  attaches_to:
  - pathophysiology#Ascending Choriodecidual Microbial Colonization
  - pathophysiology#Ascending Intraamniotic Infection After Rupture
  rationale: >-
    This entry deliberately splits colonisation before rupture from infection after it,
    because the literature very largely cannot. Amniotic fluid is sampled after the
    membranes have opened, at which point the cavity is continuous with the vagina, so a
    positive culture is compatible with either direction. The consequence is practical:
    the fraction of PPROM that is genuinely infection-initiated is not established, and
    the observation that much intraamniotic inflammation is culture-negative is
    consistent with either a sterile mechanism or an unrecovered organism.
  proposed_experiments:
  - experiment_id: exp_pprom_pre_rupture_sampling
    name: Pre-rupture longitudinal sampling in a high-risk cohort
    description: >-
      Serial cervicovaginal and, where amniocentesis is independently indicated,
      amniotic sampling with molecular microbiology in a cohort at high risk of PPROM,
      so that organism presence is established before the barrier fails rather than
      after.
    would_support:
    - pathophysiology#Ascending Choriodecidual Microbial Colonization
    supporting_outcome:
    - >-
      Organisms detectable in the amniotic cavity before rupture in a substantial
      fraction of women who subsequently rupture, at rates exceeding matched women who
      do not.
    refuting_outcome:
    - >-
      Pre-rupture sampling is sterile in most women who go on to rupture, placing the
      recovered organisms after the event and reducing the infectious route to a
      minority mechanism.
  evidence:
  - reference: PMID:32591087
    reference_title: Antibiotic administration reduces the rate of intraamniotic inflammation in preterm prelabor rupture of the membranes.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "sterile intraamniotic inflammation was defined as the presence of intraamniotic inflammation without microbial invasion of the amniotic cavity"
    explanation: >-
      The existence of a named, operationalised sterile category is what makes the
      direction question answerable rather than rhetorical.
- discussion_id: gap_pprom_no_mondo_term_for_preterm_birth
  kind: KNOWLEDGE_GAP
  status: OPEN
  prompt: >-
    Why is there no MONDO term for preterm birth itself, when PPROM - one of its causes -
    has one?
  attaches_to:
  - disease#Preterm Premature Rupture of the Membranes
  rationale: >-
    Searching MONDO for preterm birth, premature birth, preterm labor and obstetric
    labor complication returns no general term for the condition; the only anchorable
    obstetric concept in this area is preterm premature rupture of the membranes
    (MONDO:0012511), which is why this entry exists in this shape. Preterm birth is
    available in HPO as a phenotype (HP:0001622 Premature birth, with the WHO severity
    strata HP:0025664, HP:0025665 and HP:0025666), so the gap is specifically a disease
    anchor. This is the same class of blocker that issue 7837 records for postpartum
    haemorrhage. It is recorded here as a gap rather than worked around, and it is worth
    a MONDO new-term request.
  notes: >-
    Note also that MONDO classifies MONDO:0012511 under hereditary disease - it is
    reachable from MONDO:0003847 - which fits the SERPINH1 susceptibility literature the
    OMIM entry rests on but not the multifactorial entity this file curates. Worth
    raising upstream alongside the missing preterm-birth term.
differential_diagnoses:
- name: Urinary incontinence in pregnancy
  description: >-
    The commonest benign explanation for reported fluid loss in the third trimester, and
    the one that makes sterile speculum confirmation rather than history the diagnostic
    step.
- name: Increased physiological vaginal discharge
  description: >-
    Leucorrhoea increases in late pregnancy and is reported as wetness. It is
    distinguished on speculum examination by the absence of pooling.
- name: Term premature rupture of the membranes
  description: >-
    The same lesion at or after 37 weeks. It is a different entity for management
    purposes - induction rather than latency - and the mechanism literature treats term
    rupture as the physiological endpoint of the same senescence process rather than as
    a disease.
- name: Placental abruption
  description: >-
    Shares a mechanism with PPROM through decidual haemorrhage and thrombin, and the two
    co-occur, so it is a differential and a comorbidity at once. It is distinguished by
    pain, bleeding and uterine tone rather than by fluid loss.
notes: >-
  Scope. This entry is about the membrane failure, not about preterm birth. That is
  partly a modelling choice and partly forced: MONDO has no term for preterm birth (see
  the discussion entry above), so PPROM is the only anchorable disease concept in this
  part of obstetrics, and it happens to be the single largest identifiable route to the
  outcome. Spontaneous preterm labour with intact membranes is a sibling entity with
  overlapping causes and a different tissue failure, and it is not covered here.

  What the pathograph asserts and does not. The chain from oxidative stress through
  senescence to microfractures to mechanical failure is the contemporary model of a
  research group that has argued it consistently; it is well evidenced at each node and
  under-evidenced between some of them, and the causal_link_type values record which is
  which. The infectious route is modelled in parallel rather than upstream, because the
  directionality problem set out in the second discussion entry means the literature
  cannot generally place organisms before the rupture.

  Treatment edges. Three of the four treatments here target consequences rather than
  mechanisms - corticosteroids target neonatal respiratory distress, magnesium sulphate
  targets the sequelae of preterm birth, expectant management targets the timing of
  delivery. Only latency antibiotics point at a pathophysiology node, and even that edge
  points at the post-rupture infection rather than at any cause of the rupture. There is
  no treatment in current practice that acts on the membrane-failure chain, which is the
  clearest statement of where this disease stands.

  Diagnosis. The diagnosis section records two different acts that are easy to conflate.
  Confirming the rupture is a bedside question answered by the speculum examination and,
  where that is equivocal, by nitrazine, ferning or a marker-protein immunoassay; the
  accuracy figures curated there are all against a post-delivery or follow-up reference
  standard, because there is no independent gold standard available at presentation.
  Assessing the amniotic cavity after the rupture - amniocentesis, IL-6, MMP-8 - is a
  separate question, about the state of the inflammation node rather than about whether
  the membranes are open, and it is what the management decision turns on. Neither
  answers the question this disease most needs answered, which is whether a membrane is
  about to fail: nothing in current practice detects the mechanical-failure node before
  it becomes a rupture.

  Terminology. The literature uses both premature and prelabor/prelabour for the second
  P, and both spellings appear in the cited titles. MONDO's label uses premature, which
  this entry follows for the primary name; the synonyms carry the alternatives.

📚

References & Deep Research

References

3

PMID:28807394

Preterm prelabor rupture of the membranes: A disease of the fetal membranes.

No top-level findings curated for this source.

PMID:32785751

Novel pathways of inflammation in human fetal membranes associated with preterm birth and preterm pre-labor rupture of the membranes.

No top-level findings curated for this source.

PMID:18205191

A 12-bp deletion in the 5'-flanking region of the SERPINH1 gene affects promoter activity and protects against preterm premature rupture of membranes in African Americans.

No top-level findings curated for this source.

Preterm Premature Rupture of the Membranes

Ask OpenScientist

OpenScientist Report

Classifications

Mappings

Subtypes

Discussions and Knowledge Gaps

Pathophysiology

Histopathology

Pathograph

Phenotypes

Genetic Associations

Medical Actions

Environmental Factors

Biochemical Markers

Diagnosis

Prevalence

Clinical Burden

Differential Diagnoses

Clinical Trials

Source YAML

References & Deep Research

References