Abstract: We included 11 trials reporting results for 3403 women evaluating the effects of vaginal cleansing (eight using povidone-iodine, two chlorhexidine, one benzalkonium chloride) on post-cesarean infectious morbidity. Additionally, some trials used vaginal preparations using sponge sticks, douches, or soaked gauze wipes. The control groups were typically no vaginal preparation (eight trials) or the use of a saline vaginal preparation (three trials). The risk of bias in the studies reduced our confidence in the results for endometritis outcomes. Vaginal preparation with antiseptic solution immediately before cesarean delivery probably reduces the incidence of post-cesarean endometritis from 8.7% in control groups to 3.8% in vaginal cleansing groups (average risk ratio (RR) 0.36, 95% confidence interval (CI) 0.20 to 0.63, 10 trials, 3283 women, moderate quality of evidence). Subgroup analysis could not rule out larger reductions in endometritis with antiseptics in women who were in labor or in women whose membranes had ruptured when antiseptics were used. Risks of postoperative fever and postoperative wound infection may be slightly lowered by antiseptic preparation, but the confidence intervals around the effects for both outcomes are consistent with a large reduction in risk and no difference between groups (fever: RR 0.87 (0.72 to 1.05; wound infection: RR 0.74 (95% CI 0.49 to 1.11), both moderate-quality evidence). Two trials reported a lower risk of a composite outcome of wound complication or endometritis in women receiving preoperative vaginal preparation (RR 0.46, 95% CI 0.26 to 0.82, two trials, 499 women, moderate-quality evidence). No adverse effects were reported with either the povidone-iodine or chlorhexidine vaginal cleansing. Vaginal preparation with povidone-iodine or chlorhexidine solution compared to saline or not cleansing immediately before cesarean delivery probably reduces the risk of post-cesarean endometritis. Subgroup analysis could not rule out larger reductions in endometritis with antiseptics in women who were in labor or in women whose membranes had ruptured when antiseptics were used. The quality of the evidence using GRADE was moderate for all reported outcomes. We downgraded the outcome of post-cesarean endometritis and composite of wound complications or endometritis for risk of bias and postoperative fever and postoperative wound infections for wide CIs. As a simple, generally inexpensive intervention, providers may consider implementing preoperative vaginal cleansing with povidone-iodine or chlorhexidine before performing cesarean deliveries.

Plain-language summary: We searched for evidence on July 10, 2017. In this update, we have included 11 randomized controlled studies, involving a total of 3403 women undergoing cesarean section. Eight studies used povidone-iodine for vaginal cleansing, two chlorhexidine, and one benzalkonium chloride. The quality of the evidence using GRADE was moderate for the reported outcomes. We found that cleansing the vagina with an antiseptic solution compared to not cleansing or using saline or water immediately before the cesarean delivery more than halved the risk of post-cesarean infection of the uterus from a rate of 8.7% down to a rate of 3.8% (10 studies, 3283 women). While we should be cautious about results found for women in certain groups, we did also find that the benefit was also seen if the woman's waters had already broken (from 17.9% to 4.3% with vaginal cleansing; three studies, 272 women) and if women were already in labor at the time of the cesarean delivery (from a rate of 11.1% down to 4.7% with vaginal cleansing; four studies, 960 women women). The benefits were similar using both povidone-iodine and chlorhexidine. The risk of experiencing a fever (eight studies, 3109 women) or wound infection (eight studies, 2839 women) after the cesarean delivery may be slightly lowered by antiseptic preparation, but the results were not entirely clear. Only the composite outcome of wound complication or endometritis was reduced overall for women receiving preoperative vaginal cleansing (two studies, 499 women). None of the reports mentioned that any women had adverse events such as an allergic reaction to the cleansing solution or irritation. Cleansing the vagina immediately before a cesarean delivery with either an iodine-based or chlorhexidine-based solution probably reduces the risk of infection of the uterus after a cesarean section. This benefit may be greater for women who have their cesarean delivery after their membranes have already ruptured or they are already in labor. This is a generally simple, well-tolerated way to lower the chances of developing an infection after having a baby by cesarean.