A randomized trial of the bactericidal effects of chlorhexidine vs. povidone iodine vaginal preparation

BAROUYR AJEMIAN; YIPING W. HAN; CASSANDRA R. DUFFY; MARA ROXANA RUBINSTEIN; JEEWON GARCIA-SO; CYNTHIA GYAMFI-BANNERMAN

Grapevine, Texas

Conferencia; 40th SMFM Annual Pregnancy Meeting; 2020

Society for Maternal-Fetal Medicine (SMFM)

ObjectivePrecesarean vaginal preparation significantly reduces postpartum infections. While povidone iodine (PI) is the most commonly used vaginal antiseptic, evidence suggests that chlorhexidine gluconate (CHG) is more effective. Our objective was to compare the bactericidal effect of these agents on vaginal bacteria colony counts.Study DesignWe conducted a prospective randomized trial of 0.5% CHG vs. 10% PI vs. saline vaginal preparation in women undergoing cesarean delivery at ≥ 34 weeks gestation. Women in labor or those with ruptured membranes, chorioamnionitis, abnormal placentation, recent antibiotic exposure or allergy to study agents were excluded. Sterile vaginal cultures were collected in the operating room immediately prior to and five to ten minutes after vaginal cleansing with three sponge sticks. Specimens underwent serial dilutions and incubation on Tryptic Soy Agar for seven days. Our primary outcome was post-intervention aerobic and anaerobic bacterial colony counts, assessed by blinded investigators. Two-way ANOVA with simple-effects analysis and Tukey?s post test were used for multiple group comparisons. Secondary outcomes included adverse events and maternal infections.ResultsTwenty-nine women consented and underwent CHG (n=10), PI (n=9), or saline (n=10) vaginal preparation prior to cesarean delivery. Groups were similar with respect to maternal age, BMI, race, ethnicity, parity, GBS status, and gestational age at delivery. Vaginal preparation with PI resulted in lower aerobic and anaerobic bacteria colony counts compared to CHG and saline. There were no differences in baseline colony counts. PI eliminated over 99.9% of bacteria, while CHG and saline eliminated over 99% and 95%, respectively (Figure). While all agents decreased both aerobic and anaerobic bacteria, CHG performed no better than saline in reducing anaerobic bacteria. There were no reported side effects or postpartum infections.ConclusionCompared to CHG, PI was more effective at reducing vaginal bacterial colony counts in pregnancy and may be a superior vaginal antiseptic for reducing postpartum infections.