Single versus dual antibiotic regimen in women with term prolonged rupture of membranes and intrapartum fever: a retrospective study.

Objectives: The impact of E. coli in causing peripartum infections has been increasing due to rising ampicillin resistance. In this study, we compared maternal and neonatal outcomes of women with prolonged rupture of membranes (ROM >18h) and intrapartum fever, according to two antibiotic regimens they received, and describe the bacterial distribution focusing on risk factors for Enterobacteriaceae-related infectious morbidity.

Study Design: This 10-year retrospective study of women with ROM >18h and intrapartum fever included 62 women who were treated with ampicillin and gentamicin due to suspected intraamniotic infection and 79 without these signs who were treated with ampicillin alone. The primary outcomes were endometritis and neonatal early-onset sepsis (EOS) rates. Outcomes were compared using univariate and multivariate analyses.

Results: Among women who received ampicillin alone compared with dual therapy, rates were higher of endometritis (16.5% vs. 3.2%, p<0.001), neonatal early onset sepsis (7.5% vs. 0%, p=0.03), Enterobacteriaceae positive placental swab culture (67.9% vs. 15.7%, p<0.001), and histopathological subchorionitis (25.3% vs. 8.0%, p=0.008). Over 83% of Enterobacteriaceae isolates were ampicillin-resistant. Gestational age at delivery >41 weeks, meconium at delivery, ROM >24h and treatment with a single antibiotic agent were associated with the presence of a positive Enterobacteriaceae placental swab culture.

Conclusion: Ampicillin compared to dual treatment in women with prolonged ROM and fever might promote the growth of ampicillin-resistant Enterobacteriaceae (including E.coli) and increase risks of maternal and neonatal infectious morbidity.