ANTIBIOTIC-TREATMENT OF PRETERM LABOR WITH INTACT MEMBRANES - A MULTICENTER, RANDOMIZED, DOUBLE-BLINDED, PLACEBO-CONTROLLED TRIAL

OBJECTIVE: Although an association between subclinical intrauterine in fection and preterm birth is well established, there is conflicting ev idence regarding the benefits of antibiotic administration to women in preterm labor with intact membranes. We attempted to determine the ef fect of ampicillin-amoxicillin and erythromycin treatment on prolongat ion of pregnancy, the rate of preterm birth, and neonatal morbidity in patients with preterm labor and intact membranes. STUDY DESIGN: A mul ticenter, randomized, double-blinded, placebo-controlled trial was des igned and implemented by the Maternal-Fetal Medicine Units Network of the National Institute of Child Health and Human Development. Two hund red seventy-seven women with singleton pregnancies and preterm labor w ith intact membranes (24 to 34 weeks) were randomly allocated to recei ve either antibiotics or placebos. RESULTS: Of the 2373 patients scree ned for participation in this study in six medical centers, 277 women were enrolled (n = 133 for antibiotics group vs n = 144 for placebo gr oup). In each study group, 60% of patients completed all the study med ications. The overall prevalence of microbial invasion of the amniotic cavity was 5.8% (14/239). No significant difference between the antib iotic group and the placebo group was found in maternal outcomes, incl uding duration of randomization-to-delivery interval, frequency of pre term delivery (<37 weeks), frequency of preterm premature rupture of m embranes, clinical chorioamnionitis, endometritis, and number of subse quent admissions for preterm labor. Similarly, no significant differen ce in neonatal outcomes could be detected between the two groups inclu ding respiratory distress syndrome, bronchopulmonary dysplasia, intrav entricular hemorrhage, sepsis, and admission and duration of newborn i ntensive special care unit hospitalization. CONCLUSION: The results of this study do not support the routine use of antibiotic administratio n to women in preterm labor with intact membranes.