Preterm Premature Rupture of Membranes

Rupture of the fetal membranes before 37 weeks gestation and before the onset of labor (PPROM), distinct from term PROM (see next entry).

Carries risks of chorioamnionitis, cord prolapse, placental abruption, and, with prolonged rupture at early gestations, pulmonary hypoplasia and limb contractures.

A sudden gush or persistent trickle of clear or blood-stained fluid from the vagina, before 37 weeks and without regular painful contractions.

Fever, uterine tenderness, tachycardia, and offensive discharge suggest evolving chorioamnionitis.

• Sterile speculum examination (avoid digital vaginal examination unless labor is suspected, given infection risk) to visualize pooling of amniotic fluid in the posterior fornix, confirming the diagnosis
• If not visually obvious, testing for placental alpha microglobulin-1 (PAMG-1) or insulin-like growth factor binding protein-1 (IGFBP-1) in vaginal fluid supports diagnosis where clinical assessment is equivocal
• Ultrasound assesses liquor volume and fetal presentation
• FBC and CRP support monitoring for evolving infection; high vaginal and low vaginal swabs for group B streptococcus and other organisms

• Admission for close monitoring of maternal temperature, fetal heart rate, and signs of chorioamnionitis
• Prophylactic antibiotics: erythromycin 250 mg PO qds for 10 days, reduces the risk of chorioamnionitis and prolongs latency to delivery (co-amoxiclav is specifically avoided given an association with neonatal necrotizing enterocolitis in the ORACLE trial)
• Corticosteroids (betamethasone) for anticipated preterm delivery
• Magnesium sulfate for neuroprotection if delivery under roughly 30 to 32 weeks is anticipated, as per Preterm Labour entry
• Chorioamnionitis (fever, uterine tenderness, maternal or fetal tachycardia, offensive liquor) mandates prompt delivery regardless of gestation, alongside IV broad-spectrum antibiotics (commonly a combination such as IV amoxicillin/ampicillin plus gentamicin, or per local sepsis protocol) and supportive management as for sepsis (see that entry)
• Expectant management is generally continued until 34 to 37 weeks in the absence of infection or other complication, balancing prematurity risk against infection risk, with the specific gestation threshold for planned delivery guided by local protocol and specialist input
• Group B streptococcus prophylaxis in labor as per Preterm Labour entry

Referral: obstetric-led care with neonatal input; urgent escalation for any sign of chorioamnionitis.