Objective: To report a case series of adverse perinatal outcomes associated with resistant Enterobacteriaceae after antibiotic usage for premature rupture of the membranes (PROM) and group B streptococcus.
Methods: Maternal and neonatal records were reviewed of four cases in which adverse perinatal outcomes occurred from resistant Enterobacteriaceae after antibiotic usage for either PROM or positive group B streptococcal cultures. Information on clinical setting, antibiotic usage, maternal and neonatal complications, and maternal and neonatal cultures was noted.
Results: All four cases were complicated by PROM at 25-35 weeks' gestation. Ampicillin or amoxicillin was used in several clinical settings, including therapeutically for the presence of group B streptococcus, presumptively for PROM, and prophylactically pending the results of group B streptococcal cultures. Clinical chorioamnionitis subsequently developed in all four cases, and in two cases the maternal course was prolonged and complicated by persistent fever and the need for therapy for pelvic vein thrombophlebitis. Two neonates died from fulminant clinical sepsis. A third infant, one of a twin gestation, was stillborn, presumably because of sepsis. In three cases, neonatal and placental cultures revealed Escherichia coli resistant to ampicillin; in the fourth case, Klebsiella pneumoniae was identified, with only intermediate sensitivity to ampicillin.
Conclusion: Resistant Enterobacteriaceae associated with adverse perinatal outcomes may result from the use of antibiotics, such as ampicillin or amoxicillin, after PROM. In deciding whether antibiotic therapy for PROM or group B streptococcal prophylaxis is appropriate, the value of purported benefits must be weighed against presumably infrequent but serious outcomes, including neonatal sepsis and death due to selection or overgrowth of resistant organisms.