Vaginal preparation with antiseptic solution before cesarean section for preventing postoperative infections

Cesarean delivery is one of the most common surgical procedures performed by obstetricians. Infectious morbidity after cesarean delivery can have a tremendous impact on the postpartum woman's return to normal function and her ability to care for her baby. Despite the widespread use of prophylactic antibiotics, postoperative infectious morbidity still complicates cesarean deliveries. This is an update of a Cochrane Review first published in 2010 and subsequently updated in 2012, twice in 2014, in 2017 and 2018.

To determine if cleansing the vagina with an antiseptic solution before a cesarean delivery decreases the risk of maternal infectious morbidities, including endometritis and wound complications. We also assessed the side effects of vaginal cleansing solutions to determine adverse events associated with the intervention.

We searched the Cochrane Pregnancy and Childbirth's Trials Register, ClinicalTrials.gov, the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) (7 July 2019), and reference lists of retrieved studies.

We included randomized controlled trials (RCTs) and quasi-RCTs assessing the impact of vaginal cleansing immediately before cesarean delivery with any type of antiseptic solution versus a placebo solution/standard of care on post-cesarean infectious morbidity. Cluster-RCTs were eligible for inclusion, but we did not identify any. We excluded trials that utilized vaginal preparation during labor or that did not use antibiotic surgical prophylaxis. We also excluded any trials using a cross-over design. We included trials published in abstract form only if sufficient information was present in the abstract on methods and outcomes to analyze.

At least three of the review authors independently assessed eligibility of the studies. Two review authors were assigned to extract study characteristics, quality assessments, and data from eligible studies.

We included 21 trials, reporting results for 7038 women evaluating the effects of vaginal cleansing (17 using povidone-iodine, 3 chlorhexidine, 1 benzalkonium chloride) on post-cesarean infectious morbidity. Trials used vaginal preparations administered by sponge sticks, douches, or soaked gauze wipes. The control groups were typically no vaginal preparation (17 trials) or the use of a saline vaginal preparation (4 trials). One trial did not report on any outcomes of interest. Trials were performed in 10 different countries (Saudi Arabia, Pakistan, Iran, Thailand, Turkey, USA, Egypt, UK, Kenya and India). The overall risk of bias was low for areas of attrition, reporting, and other bias. About half of the trials had low risk of selection bias, with most of the remainder rated as unclear. Due to lack of blinding, we rated performance bias as high risk in nearly one-third of the trials, low risk in one-third, and unclear in one-third. Vaginal preparation with antiseptic solution immediately before cesarean delivery probably reduces the incidence of post-cesarean endometritis from 7.1% in control groups to 3.1% in vaginal cleansing groups (average risk ratio (aRR) 0.41, 95% confidence interval (CI) 0.29 to 0.58; 20 trials, 6918 women; moderate-certainty evidence). This reduction in endometritis was seen for both iodine-based solutions and chlorhexidine-based solutions. Risks of postoperative fever and postoperative wound infection are also probably reduced by vaginal antiseptic preparation (fever: aRR 0.64, 0.50 to 0.82; 16 trials, 6163 women; and wound infection: RR 0.62, 95% CI 0.50 to 0.77; 18 trials, 6385 women; both moderate-certainty evidence). Two trials found that there may be 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; 2 trials, 499 women; low-certainty evidence). No adverse effects were reported with either the povidone-iodine or chlorhexidine vaginal cleansing. Subgroup analysis suggested a greater effect with vaginal preparations for those women in labour versus those not in labour for four out of five outcomes examined (post-cesarean endometritis; postoperative fever; postoperative wound infection; composite wound complication or endometritis). This apparent difference needs to be investigated further in future trials. We did not observe any subgroup differences between women with ruptured membranes and women with intact membranes.

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, postoperative fever, and postoperative wound infection. Subgroup analysis found that these benefits were typically present whether iodine-based or chlorhexidine-based solutions were used and when women were in labor before the cesarean. The suggested benefit in women in labor needs further investigation in future trials. There was moderate-certainty evidence using GRADE for all reported outcomes, with downgrading decisions based on limitations in study design or imprecision. As a simple intervention, providers may consider implementing preoperative vaginal cleansing with povidone-iodine or chlorhexidine before performing cesarean deliveries. Future research on this intervention being incorporated into bundles of care plans for women receiving cesarean delivery will be needed.