Routine antibiotic prophylaxis after normal vaginal birth for reducing maternal infectious morbidity

Infectious morbidities contribute to considerable maternal and perinatal morbidity and mortality, including women at no apparent increased risk of infection. To reduce the incidence of infections, antibiotics are often administered to women after uncomplicated childbirth, particularly in settings where women are at higher risk of puerperal infectious morbidities.

To assess whether routine administration of prophylactic antibiotics to women after normal (uncomplicated) vaginal birth, compared with placebo or no antibiotic prophylaxis, reduces postpartum maternal infectious morbidities and improves outcomes.

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (31 August 2017), LILACS, ClinicalTrials.gov, the WHO International Clinical Trials Registry Platform (ICTRP) (22 August 2017) and reference lists of retrieved studies.

We planned to include randomised or quasi-randomised trials evaluating the use of prophylactic antibiotics versus placebo or no antibiotic prophylaxis. Trials using a cluster-randomised design would have been eligible for inclusion, but we found none.In future updates of this review, we will include studies published in abstract form only, provided sufficient information is available to assess risks of bias. We will consider excluded abstracts for inclusion once the full publication is available, or the authors provide more information.Trials using a cross-over design are not eligible for inclusion in this review.

Two review authors conducted independent assessment of trials for inclusion and risks of bias. They independently extracted data and checked them for accuracy, resolving differences in assessments by discussion. They evaluated methodological quality using standard Cochrane criteria and the GRADE approach.We present the summaries as risk ratios (RRs) and mean difference (MDs) using fixed- or random-effect models. For one primary outcome we found considerable heterogeneity and interaction. We explored further using subgroup analysis to investigate the effects of the randomisation unit. All review authors discussed and interpreted the results.

One randomised controlled trial (RCT) and two quasi-RCTs contributed data on 1779 women who had uncomplicated vaginal births, comparing different antibiotic regimens with placebo or no treatment. The included trials took place in the 1960s (one trial) and 1990s (two trials). The trials were conducted in France, the USA and Brazil. Antibiotics administered included: oral sulphamethoxypyridazine or chloramphenicol for three to five days, and intravenous amoxicillin and clavulanic acid in a single dose one hour after birth. We rated most of the domains for risk of bias as high risk, with the exception of reporting bias and other potential bias.The quality of evidence ranged from low to very low, based on the GRADE quality assessment, given very serious design limitations of the included studies, few events and wide confidence intervals (CIs) of effect estimates.We found a decrease in the risk of endometritis (RR 0.28, 95% CI 0.09 to 0.83, two trials, 1364 women,very low quality). However, one trial reported zero events for this outcome and we rate the evidence as very low quality. There was little or no difference between groups for the risk of urinary tract infection (RR 0.25, 95% CI 0.05 to 1.19, two trials, 1706 women,low quality), wound infection after episiotomy (reported as wound dehiscence in the included trials) (RR 0.78, 95% CI 0.31 to 1.96, two trials, 1364 women, very low quality) and length of maternal hospital stay in days (MD -0.15, 95% CI -0.31 to 0.01, one trial, 1291 women, very low quality). Cost of care in US dollar equivalent was 2½ times higher in the control group compared to the group receiving antibiotics prophylaxis (USD 3600: USD 9000, one trial, 1291 women). There were few or no differences between treated and control groups for adverse effects of antibiotics (skin rash) reported in one woman in each of the two trials (RR 3.03, 95% CI 0.32 to 28.95, two trials, 1706 women, very low quality). The incidence of severe maternal infectious morbidity, antimicrobial resistance or women's satisfaction with care were not addressed by any of the included studies.

Routine administration of antibiotics may reduce the risk of endometritis after uncomplicated vaginal birth. The small number and nature of the trials limit the interpretation of the evidence for application in practice, particularly in settings where women may be at higher risk of developing endometritis. The use of antibiotics did not reduce the incidence of urinary tract infections, wound infection or the length of maternal hospital stay. Antibiotics are not a substitute for infection prevention and control measures around the time of childbirth and the postpartum period. The decision to routinely administer prophylactic antibiotics after normal vaginal births needs to be balanced by patient features, childbirth setting and provider experience, including considerations of the contribution of indiscriminate use of antibiotics to raising antimicrobial resistance. Well-designed and high-powered randomised controlled trials would help to evaluate the added value of routine antibiotic administration as a measure to prevent maternal infections after normal vaginal delivery.