Background: Prelabour rupture of the membranes (PROM) at or near term (defined in this review as 36 weeks' gestation or beyond) increases the risk of infection for the woman and her baby. The routine use of antibiotics for women at the time of term PROM may reduce this risk. However, due to increasing problems with bacterial resistance and the risk of maternal anaphylaxis with antibiotic use, it is important to assess the evidence addressing risks and benefits in order to ensure judicious use of antibiotics. This review was undertaken to assess the balance of risks and benefits to the mother and infant of antibiotic prophylaxis for PROM at or near term.
Objectives: To assess the effects of antibiotics administered prophylactically to women with PROM at 36 weeks' gestation or beyond, on maternal, fetal and neonatal outcomes.
Search methods: We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (31 July 2014).
Selection criteria: All randomised trials that compared outcomes for women and infants when antibiotics were administered prophylactically for prelabour rupture of the membranes at or near term, with outcomes for controls (placebo or no antibiotic).
Data collection and analysis: Two review authors independently extracted the data and assessed risk of bias in the included studies. Additional data were received from the investigators of included studies.
Main results: This update includes an additional two studies involving 1801 women, giving a total of four included studies of 2639 women. Whereas the previous version of this review showed a statistically significant reduction in endometritis with the use of antibiotics, no such effect was shown in this update (average risk ratio (RR) 0.34, 95% confidence interval (CI) 0.05 to 2.31). No differences were shown on the primary outcome measures of probable early-onset neonatal sepsis (average RR 0.69, 95%; CI 0.21 to 2.33); definite early-onset neonatal sepsis (average RR 0.57, 95% CI 0.08 to 4.26); maternal infectious morbidity (chorioamnionitis and/or endometritis) (average RR 0.48, 95% CI 0.20 to 1.15); stillbirth (RR 3.00, 95% CI 0.61 to 14.82); and perinatal mortality (RR 1.98, 95% CI 0.60 to 6.55), though the number of cases in the control group for these outcomes was low. There were no cases of neonatal mortality or serious maternal outcome in the studies assessed. Caesarean section was increased with the use of antibiotics (RR 1.33, 95% CI 1.09 to 1.61) as was duration of maternal stay in hospital (mean difference (MD) 0.06 days, 95% CI 0.01 to 0.11), largely owing to one study of 1640 women where repeat caesarean section, increased baseline hypertension and pre-eclampsia were evident in the antibiotic group, despite random allocation and allocation concealment.Subgroup analyses by timing of induction (early induction versus late induction) showed no difference in either probable or definite early-onset neonatal sepsis in the early induction group (RR 1.47, 95% CI 0.80 to 2.70 and RR 1.29, 95% CI 0.48 to 3.44, respectively) or the late induction group (RR 0.14, 95% CI 0.02 to 1.13 and RR 0.16, 95% CI 0.02 to 1.34, respectively), although there were trends toward reduced probable and definite early-onset neonatal sepsis in the late induction group. A test for subgroup differences confirmed a differential effect of the intervention on probable early-onset neonatal sepsis between the subgroups (Chi² = 4.50, df = 1 (P = 0.03), I² = 77.8%). No difference in maternal infectious morbidity (chorioamnionitis and/or endometritis) was found in either subgroup, though again there was a trend towards reduced maternal infectious morbidly in the late induction group (average RR 0.34, 95% CI 0.08 to 1.47). No differences were shown in stillbirth or perinatal mortality. The quality of the evidence for the primary outcomes using GRADE was judged to be low to very low.
Authors' conclusions: This updated review demonstrates no convincing evidence of benefit for mothers or neonates from the routine use of antibiotics for PROM at or near term. We are unable to adequately assess the risk of short- and long-term harms from the use of antibiotics due to the unavailability of data. Given the unmeasured potential adverse effects of antibiotic use, the potential for the development of resistant organisms, and the low risk of maternal infection in the control group, the routine use of antibiotics for PROM at or near term in the absence of confirmed maternal infection should be avoided.