Randomized trial of prophylactic antibiotic therapy after preterm amnion rupture.
Our purpose was to determine whether maternal administration of prophylactic ampicillin or erythromycin after preterm amnion rupture is associated with maternal or neonatal benefits.
                Women with singleton pregnancies between 24 and 33 weeks 6 days of gestation were eligible if they had no immediate indication for delivery. After giving informed consent, patients were randomized either to receive ampicillin (erythromycin if penicillin allergic) until delivery or to enter a control group. Women whose cervical cultures were positive for either group B streptococci or Neisseria gonorrhoeae received treatment. Tocolytics and corticosteroids were not used.
                From January 1990 to February 1992 117 patients (antibiotics 59, control 58) were recruited and analyzed. Prophylactic antibiotics were associated with a longer latent phase (mean 12 vs 7.0 days, p = 0.004) and fewer maternal infectious complications (29% vs 60%, p = 0.001). A higher incidence of neonatal necrotizing enterocolitis was observed in the treatment group (14% vs 3.5%, p = 0.05). Other neonatal complications, including death, were lower in the treatment group, but none attained statistical significance (p = 0.09 to 0.33).
                The use of prophylactic antibiotics in selected patients after preterm amnion rupture appears to have a demonstrable maternal benefit. Large, multicenter trials may demonstrate a significant neonatal benefit or confirm any adverse outcomes.
There are insufficient data from randomized controlled trials to guide clinical practice. A large randomized controlled trial is needed in asymptomatic term infants born to mothers with risk factors for infection in their babies, which compares the effect of prophylactic versus selective antibiotics on morbidity, mortality and costs.