Time to reconsider antibiotic prophylaxis in women with prolonged rupture of membranes: The trend of Enterobacteriaceae in peripartum infections

Objective: The proportion of neonatal early-onset sepsis (EOS) by gram-negative bacteria has increased. The authors examined bacterial distribution in the amniotic membrane cultures of women with peripartum fever (PPF) and related perinatal outcomes. Methods: This retrospective study covered the period 2011 to 2019. The primary outcomes were Enterobacteriaceae-positive birth culture rates in women with PPF and the trend of ampicillin resistance. Maternal and neonatal outcomes were compared between women with group B Streptococcus (GBS) and Enterobacteriaceae-positive isolates. Bacterial distribution was also compared according to rupture of membrane (ROM) duration. Results: Among 621 women with PPF, the positive birth culture rate was 52%. Increasing prevalences of ampicillin-resistant Enterobacteriaceae (81%) were noted. Positive birth cultures were associated with maternal bacteremia (P = 0.017) and neonatal EOS (P = 0.003). Prolonged ROM ≥18 h was associated with increased risk for Enterobacteriaceae-positive cultures, while intrapartum ampicillin and gentamicin were associated with lower risk. Enterobacteriaceae-positive compared with GBS-positive birth cultures were associated with adverse maternal and neonatal outcomes. Conclusion: Positive birth cultures were related to maternal bacteremia and neonatal sepsis. Adverse outcomes were more prevalent among women with Enterobacteriaceae-positive versus GBS-positive birth cultures. Prolonged ROM is a risk factor for Enterobacteriaceae-positive birth cultures among women with PPF. Antibiotic prophylaxis treatment for prolonged ROM should be reconsidered.