Premature Rupture of Membranes (PROM)

Definition and Classification

• PROM at term (≥37 weeks) - rupture before labor onset
• Preterm PROM (PPROM) - rupture before 37 weeks' gestation
• Previable PROM - rupture before approximately 22-23 weeks
• The latent period = time from membrane rupture to onset of labor

Predisposing Factors

• Short cervix
• Prior history of PROM or preterm delivery
• Genital tract infection (Chlamydia, gonorrhea, Trichomonas vaginalis, bacterial vaginosis)
• Non-genital infections (pyelonephritis, pneumonia, appendicitis, periodontal disease)
• Multiple gestation / polyhydramnios
• Uterine overdistention
• Smoking
• Placental abruption

Diagnosis

Complications

Maternal Complications

• Chorioamnionitis: 9% with term PROM; rises to 24% after >24 hours of rupture; 13-35% with PPROM remote from term; up to 25-77% with second-trimester PROM on conservative management
• Endometritis: 2-13%
• Placental abruption: 4-12%
• Maternal sepsis: 0.8% (death: 0.14%) - more likely with very early preterm PROM

Fetal Complications

• Umbilical cord compression (from oligohydramnios - FHR decelerations common)
• Umbilical cord prolapse (especially with malpresentation)
• Fetal death: ~1-2% with conservatively managed PROM; 12-71% (avg ~30%) with PROM <24 weeks
• Intrauterine infection

Neonatal Complications

• Gestational age at delivery is the primary determinant of severity
• Neonatal sepsis is twice as common after PPROM versus preterm labor
• Infection can manifest as congenital pneumonia, sepsis, meningitis
• Long-term: chronic lung disease, developmental disabilities, cerebral palsy, periventricular leukomalacia, visual/hearing deficits
• Long-term morbidities are uncommon with delivery after ~32 weeks

Management (Gestational Age-Based)

Term PROM (≥37 weeks)

• Induce labor - usually with oxytocin infusion
• No substantial fetal benefit to expectant management at term
• Reduces risk of chorioamnionitis (rises with prolonged rupture)
• Allow adequate time for latent phase; minimize digital vaginal exams until active phase

Preterm PROM at 34-36 weeks (Late Preterm)

• Conservative management prolongs pregnancy by only a few days (mean ~71-78 hours) while significantly increasing chorioamnionitis risk (16% vs 2%)
• PROMEXIL trials: conservative management doubled chorioamnionitis (5.6% vs 2.3%)
• Delivery is generally recommended - active management reduces RDS (5.2% vs 8.3%), ventilator need, and NICU stay
• Antenatal corticosteroids: administer if not previously given

Preterm PROM at <34 weeks (Remote from Term)

1. Antibiotics - broad-spectrum (e.g., ampicillin + erythromycin; ACOG recommends GBS prophylaxis); prolong latency and reduce infection
2. Antenatal corticosteroids - single course (betamethasone or dexamethasone) to accelerate fetal lung maturation
3. Tocolytics - short-term, to allow time for corticosteroids to act; not for prolonged use
4. Magnesium sulfate for neuroprotection - at 24-32 weeks to reduce risk of cerebral palsy
5. GBS prophylaxis - if colonization status unknown or positive
6. Continuous fetal monitoring - assess for cord compression, infection signs
7. DVT prophylaxis - leg exercises, compression stockings (prolonged bed rest increases DVT risk)

Previable PROM (<22-23 weeks)

• Particularly high fetal jeopardy
• Survival with conservative management at ≤24 weeks: ~44% overall (14% for PROM before 22 weeks; 58% for PROM at 22-24 weeks)
• Immediate delivery → neonatal death
• Requires detailed counseling; decisions individualized

Chorioamnionitis (Complication of PROM)

• Fever >38°C
• Maternal and fetal tachycardia
• Uterine tenderness
• Foul-smelling or purulent amniotic fluid
• Elevated CRP (>2 mg/dL); WBC unreliable (normally elevated in labor)

Summary Algorithm

Confirmed PROM
    ↓
Assess: gestational age, labor status, infection signs, fetal well-being
    ↓
≥37 weeks → Induce labor (oxytocin)
34-36 weeks → Active delivery (steroids if not given)
24-33 weeks → Conservative management:
              Antibiotics + Steroids + MgSO4 (24-32wks) + Tocolysis + Monitoring
<22-23 weeks → Individualized counseling; consider viability/prognosis