What antibiotics are recommended for PROM (Premature Rupture of Membranes) prophylaxis?

Antibiotic Recommendations for Premature Rupture of Membranes (PROM) Prophylaxis

For premature rupture of membranes (PROM), the recommended antibiotic regimen is ampicillin 2g IV every 6 hours and erythromycin 250mg IV every 6 hours for 48 hours, followed by oral amoxicillin 250mg every 8 hours and erythromycin 333mg every 8 hours for 5 days. 1, 2

Recommended Antibiotic Regimens by Clinical Scenario

For Preterm PROM (PPROM) ≥24 weeks:

• A 7-day course consisting of:
  • Initial 48 hours: IV ampicillin 2g every 6 hours AND erythromycin 250mg IV every 6 hours 1, 2
  • Followed by 5 days: Oral amoxicillin 250mg every 8 hours AND erythromycin 333mg every 8 hours 1, 2
• Alternative regimen: Erythromycin 250mg orally every 6 hours for 10 days 2
• Azithromycin can be substituted for erythromycin when erythromycin is not available 3, 4

For PPROM at 20-23 6/7 weeks:

• Same antibiotic regimen as above can be considered, though with less supporting evidence (GRADE 2C recommendation) 1

For Group B Streptococcus (GBS) Prophylaxis:

• If receiving antibiotics for latency that include ampicillin 2g IV once, followed by 1g IV every 6 hours for at least 48 hours, this is adequate for GBS prophylaxis 5, 3
• For women with PPROM who are GBS positive, continue antibiotics until delivery if in labor 3
• For women with PPROM who are GBS negative, no GBS prophylaxis is needed at onset of true labor 3

Important Considerations and Precautions

• AVOID amoxicillin/clavulanic acid due to increased risk of necrotizing enterocolitis in neonates 3, 1, 2
• Oral antibiotics alone are not adequate for GBS prophylaxis 5, 3
• GBS prophylaxis should be discontinued at 48 hours for women with PPROM who are not in labor 5, 3
• If GBS screen results become available during the 48-hour period and are negative, GBS prophylaxis should be discontinued at that time 5, 3
• A negative GBS screen is considered valid for 5 weeks 5, 3

Benefits of Appropriate Antibiotic Therapy

• Prolongs pregnancy latency 1, 4
• Reduces maternal infection and chorioamnionitis 1, 4
• Decreases neonatal morbidity 1, 4
• Improves neonatal survival without severe morbidity 1

Alternative Antibiotic Regimen

Some newer research suggests a potentially more effective regimen against anaerobes and genital mycoplasmas:

• Ceftriaxone, clarithromycin, and metronidazole combination has shown:
  • Longer latency period 6, 7
  • Reduced rates of acute histologic chorioamnionitis and funisitis 6
  • Improved neonatal outcomes 6
  • Better eradication of intra-amniotic inflammation/infection 7

Special Considerations for Penicillin Allergy

• For patients allergic to penicillin, macrolide antibiotics (erythromycin or azithromycin) should be used alone 2
• Antibiotic susceptibility testing should be performed to guide alternative therapy in penicillin-allergic patients 8

Timing Considerations

• Antibiotics are indicated after 18 hours of membrane rupture regardless of other risk factors 1
• Prompt administration of antibiotics is recommended when indicated based on gestational age 1