Different methods of vaginal preparation before cesarean delivery to prevent postoperative infection: a systematic review and network meta-analysis

Precesarean vaginal antisepsis can benefit pregnant women with ruptured membranes. However, in the general population, recent trials have shown mixed results in reducing postoperative infections. This study aimed to systematically review clinical trials and summarize the most suitable vaginal preparations for cesarean delivery in preventing postoperative infection.We searched PubMed, Web of Science, Cochrane Library, SinoMed databases, and the ClinicalTrials.gov clinical trials registry for randomized controlled trials and conference presentations (past 20 years, 2003-2022). Reference lists of previous meta-analyses were searched manually. In addition, we conducted subgroup analysis on the basis of whether the studies were conducted in developed or developing countries, whether the membranes were ruptured, and whether patients were in labor.We included randomized controlled trials comparing vaginal preparation methods for the prevention of postcesarean infection with each other or with negative controls.Two reviewers independently extracted data and assessed the risk of bias and the certainty of the evidence. The effectiveness of prevention strategies was assessed by frequentist-based network meta-analysis models. The outcomes were endometritis, postoperative fever, and wound infection.A total of 23 trials including 10,026 cesarean delivery patients were included in this study. Vaginal preparation methods included 19 iodine-based disinfectants (1%, 5%, and 10% povidone-iodine; 0.4% and 0.5% iodophor) and 4 guanidine-based disinfectants (0.05% and 0.20% chlorhexidine acetate; 1% and 4% chlorhexidine gluconate). Overall, vaginal preparation significantly reduced the risks of endometritis (3.4% vs 8.1%; risk ratio, 0.41 [0.32-0.52]), postoperative fever (7.1% vs 11.4%; risk ratio, 0.58 [0.45-0.74]), and wound infection (4.1% vs 5.4%; risk ratio, 0.73 [0.59-0.90]). With regard to disinfectant type, iodine-based disinfectants (risk ratio, 0.45 [0.35-0.57]) and guanidine-based disinfectants (risk ratio, 0.22 [0.12-0.40]) significantly reduced the risk of endometritis, and iodine-based disinfectants reduced the risk of postoperative fever (risk ratio, 0.58 [0.44-0.77]) and wound infection (risk ratio, 0.75 [0.60-0.94]). With regard to disinfectant concentration, 1% povidone-iodine was most likely to simultaneously reduce the risks of endometritis, postoperative fever, and wound infection.Preoperative vaginal preparation can significantly reduce the risk of postcesarean infectious diseases (endometritis, postoperative fever, and wound infection); 1% povidone-iodine has particularly outstanding effects.