Purpose: to evaluate whether prophylactic use of ampicillin could avoid or reduce maternal and perinatal infectious morbidity caused by premature rupture of membranes (PROM), and to extend the gestation period in those women. Methods: this was a prospective, randomized and double-blind study, carried out evaluating 121 pregnant women with PROM, randomized into two study groups. The treatment group (61 patients) received ampicillin and the control group (60 patients) received placebo. The placebo had the same characteristics as ampicillin (kind of packaging and color of the capsules) and was used in the same time regimen. The considered parameters for maternal infection were febrile morbidity (fever index), and the presence of chorioamnionitis and/or endometritis. The studied neonatal parameters were Apgar score (1st and 5th minutes), bacterial colonization of auditory canal, and blood culture. The statistical tests performed were Fisher's exact test, Wilcoxon, and chi². Results: it was observed that ampicillin did not prolong the gestation, nor did it reduce the postpartum febrile morbidity or the rates of chorioamnionitis and/or endometritis. Ampicillin did not reduce the perinatal infectious morbidity nor improve the birth outcomes. All these results were consistent in cases of less than 72 h PROM. The limited number of cases with time of PROM greater than 72 h did not permit statistical analysis free of type II error. Conclusions: based on these results it was possible to conclude that the prophylactic use of ampicillin by pregnant women with less than 72 h PROM did not reduce either infectious maternal or perinatal morbidity. However, the presence of group B Streptococcus agalactiae in the blood culture from a neonate in the control group showed the necessity to start antibiotic treatment of pregnant women colonized by this microorganism.
Premature rupture of membranes; Antibiotic prophylaxis; Postpartum febrile morbidity
