Antibiotic Recommendations for Ruptured Membranes
For patients with ruptured membranes (premature rupture of membranes), antibiotics should be administered based on gestational age: ampicillin plus erythromycin is recommended for patients ≥24 weeks, while antibiotics can be considered but have less evidence for those between 20-23 6/7 weeks. 1
Antibiotic Regimens Based on Gestational Age
≥24 Weeks Gestation
- Recommended 7-day course: ampicillin 2g IV every 6 hours and erythromycin 250mg IV every 6 hours for 48 hours, followed by amoxicillin 250mg orally every 8 hours and erythromycin 333mg orally every 8 hours for 5 days 2, 3
- Alternative regimen: erythromycin 250mg orally every 6 hours for 10 days 3
- Azithromycin may be substituted for erythromycin in these regimens 2
20-23 6/7 Weeks Gestation
- Antibiotics can be considered but have less supporting evidence (GRADE 2C recommendation) 1
- Same regimens as above may be used if antibiotics are administered 2
Important Cautions
- Amoxicillin/clavulanic acid should NOT be used due to increased risk of necrotizing enterocolitis in neonates 3
- For penicillin-allergic patients, use macrolide antibiotics (erythromycin) alone 3
Duration of Antibiotic Therapy
- Standard duration is 7 days total (including both IV and oral phases) 2, 3
- Prophylactic antibiotics are indicated after 18 hours of membrane rupture regardless of other risk factors 4
Special Considerations
Monitoring During Expectant Management
- Regular assessment for signs of infection: fever >38.0°C, uterine tenderness, fetal tachycardia, and purulent vaginal discharge 4, 5
- Monitor maternal vital signs, fetal heart rate, and laboratory evaluation for leukocytosis 5
- For outpatient management, patients should monitor for fever, contractions, vaginal bleeding, discolored discharge, and abdominal pain 5
Benefits of Antibiotic Therapy
- Prolongs pregnancy latency period (average 7.34 days with antibiotics vs 1.86 days without) 6
- Reduces maternal and neonatal infectious morbidity 2, 3
- Decreases risk of chorioamnionitis 2
Timing Considerations
- Risk of infection increases significantly after 18 hours of membrane rupture 4
- In cases with ruptured membranes >18 hours, antibiotic prophylaxis is indicated regardless of other risk factors 1, 4
Additional Testing
- Screen all patients with PPROM for urinary tract infections, sexually transmitted infections, and Group B Streptococcus carriage 3
- Treat with appropriate antibiotics if any screening tests are positive 3
Pitfalls to Avoid
- Failing to administer antibiotics promptly after 18 hours of membrane rupture 1, 4
- Using amoxicillin/clavulanic acid combination, which increases risk of necrotizing enterocolitis 3
- Delaying antibiotic administration in patients ≥24 weeks gestation, as evidence strongly supports antibiotic use in this population 1
- Overlooking screening for concurrent infections that may require specific antibiotic coverage 3