Abstract: Our prespecified primary outcomes were maternal and neonatal mortality, maternal and neonatal severe infection, and duration of maternal and neonatal hospital stay. We included 11 studies (involving 1296 women) and assessed them as having low to moderate risk of bias - mainly because allocation concealment methods were not adequately reported, most studies were open, and outcome reporting was incomplete. The quality of the evidence was low to very low for most outcomes, as per the GRADE approach. The following antibiotics were assessed in the included trials: ampicillin, ampicillin/sulbactam, gentamicin, clindamycin, and cefotetan. During labor: meta-analysis of two studies found no clear differences in rates of neonatal sepsis (163 neonates; risk ratio (RR) 1.07, 95% confidence interval (CI) 0.40 to 2.86; I² = 9%; low quality of evidence), treatment failure (endometritis) (163 participants; RR 0.86, 95% CI 0.27 to 2.70; I² = 0%; low quality of evidence), and postpartum hemorrhage (RR 1.39, 95% CI 0.76 to 2.56; I² = 0%; low quality of evidence) when two different dosages/regimens of gentamicin were assessed. No clear differences between groups were found for any reported maternal or neonatal outcomes. The review did not identify data for a comparison of antibiotics versus no treatment/placebo. Postpartum: meta-analysis of two studies that evaluated use of antibiotics versus placebo after vaginal delivery showed no significant differences between groups in rates of treatment failure or postpartum endometritis. No significant differences were found in rates of neonatal death and postpartum endometritis when use of antibiotics was compared with no treatment. Four trials assessing two different dosages/regimens of gentamicin or dual-agent therapy versus triple-agent therapy, or comparing antibiotics, found no significant differences in most reported neonatal or maternal outcomes; the duration of hospital stay showed a difference in favor of the group of women who received short-duration antibiotics (one study, 292 women; mean difference (MD) -0.90 days, 95% CI -1.64 to -0.16; moderate quality of evidence). Intrapartum versus postpartum: one small study (45 women) evaluating use of ampicillin/gentamicin during intrapartum versus immediate postpartum treatment found significant differences favoring the intrapartum group in the mean number of days of maternal postpartum hospital stay (one trial, 45 women; MD -1.00 days, 95% CI -1.94 to - 0.06; very low quality of evidence) and the mean number of neonatal hospital stay days (one trial, 45 neonates; MD -1.90 days, 95% CI -3.91 to -0.49; very low quality of evidence). Although no significant differences were found in the rate of maternal bacteremia or early neonatal sepsis, for the outcome of neonatal pneumonia or sepsis we observed a significant difference favoring intrapartum treatment (one trial, 45 neonates; RR 0.06, 95% CI 0.00 to 0.95; very low quality of evidence). This review included 11 studies (having low to moderate risk of bias). The quality of the evidence was low to very low for most outcomes, as per the GRADE approach. Only one outcome (duration of hospital stay) was considered to provide moderate quality of evidence when antibiotics (short duration) were compared with antibiotics (long duration) during postpartum management of intra-amniotic infection. Our main reasons for downgrading the quality of evidence were limitations in study design or execution (risk of bias), imprecision, and inconsistency of results. Currently, limited evidence is available to reveal the most appropriate antimicrobial regimen for the treatment of patients with intra-amniotic infection; whether antibiotics should be continued during the postpartum period; and which antibiotic regimen or what treatment duration should be used. Also, no evidence was found on adverse effects of the intervention (not reported in any of the included studies). One small RCT showed that use of antibiotics during the intrapartum period is superior to their use during the postpartum period in reducing the number of days of maternal and neonatal hospital stay.

Plain-language summary: a total of 11 studies were identified with 1296 women; most studies were conducted in the USA. Four studies evaluated the use of antibiotics before the birth (antepartum); six studies evaluated the use of antibiotics after birth (postpartum); and one compared antibiotic administration both before and after birth. the quality of the evidence was ranked low to very low, mainly because many studies had methodological limitations with outcome results based on limited numbers of trials and included participants that could be pooled. based on the findings of one study, treatment during labor was found to be more effective than treatment after labor; however this finding relates only to maternal and neonatal length of hospital stay and to neonatal severe infection. No evidence indicated that a higher dose of antibiotics before birth was superior to a lower dose. Immediately following birth, no evidence showed that different types of antibiotics or longer or shorter treatment duration improved the health of the mother and her newborn. All women who participated in the postpartum trials received antibiotics before the time of birth. Therefore insufficient information was available from randomized controlled trials to reveal the most appropriate regimen of antibiotics for the treatment of patients with intra-amniotic infection, whether antibiotics should be continued during the postpartum period, and which antibiotic regimen should be used and for what duration. None of the included studies reported information related to adverse effects of the intervention.