Vaginal cleansing before CD lowers risk of postop endometritis
Caissutti C, Saccone G, Zullo F, et al. Vaginal cleansing before cesarean delivery: a systematic review and meta-analysis. Obstet Gynecol. 2017;130(3):527-538.
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Caissutti and colleagues aimed to determine if cleansing the vagina with an antiseptic solution prior to surgery reduced the frequency of postcesarean endometritis. They included 16 RCTs (4,837 patients) in their systematic review and meta-analysis. The primary outcome was the frequency of postoperative endometritis.
Details of the study
The studies were conducted in several countries and included patients of various socioeconomic classes. Six trials included only patients having a scheduled CD; 9 included both scheduled and unscheduled cesareans; and 1 included only unscheduled cesareans. In 11 studies, povidone-iodine was the antiseptic solution used. Two trials used chlorhexidine diacetate 0.2%, and 1 used chlorhexidine diacetate 0.4%. One trial used metronidazole 0.5% gel, and another used the antiseptic cetrimide, which is a mixture of different quaternary ammonium salts, including cetrimonium bromide.
In all trials, patients received prophylactic antibiotics. The antibiotics were administered prior to the surgical incision in 6 trials; they were given after the umbilical cord was clamped in 6 trials. In 2 trials, the antibiotics were given at varying times, and in the final 2 trials, the timing of antibiotic administration was not reported. Of note, no trials described the method of placenta removal, a factor of considerable significance in influencing the rate of postoperative endometritis.5,6
Endometritis frequency reduced with vaginal cleansing; benefit greater in certain groups. Overall, in the 15 trials in which vaginal cleansing was compared with placebo or with no treatment, women in the treatment group had a significantly lower rate of endometritis (4.5% compared with 8.8%; relative risk [RR], 0.52; 95% CI, 0.37-0.72). When only women in labor were considered, the frequency of endometritis was 8.1% in the intervention group compared with 13.8% in the control group (RR, 0.52; 95% CI, 0.28-0.97). In the women who were not in labor, the difference in the incidence of endometritis was not statistically significant (3.5% vs 6.6%; RR, 0.62; 95% CI, 0.34-1.15).
In the subgroup analysis of women with ruptured membranes at the time of surgery, the incidence of endometritis was 4.3% in the treatment group compared with 20.1% in the control group (RR, 0.23; 95% CI, 0.10-0.52). In women with intact membranes at the time of surgery, the incidence of endometritis was not significantly reduced in the treatment group.
Interestingly, in the subgroup analysis of the 10 trials that used povidone-iodine, the reduction in the frequency of postcesarean endometritis was statistically significant (2.8% vs 6.3%; RR, 0.42; 95% CI, 0.25-0.71). However, this same protective effect was not observed in the women treated with chlorhexidine. In the 1 trial that directly compared povidone-iodine with chlorhexidine, there was no statistically significant difference in outcome.
Simple intervention, solid benefit
Endometritis is the most common complication following CD. The infection is polymicrobial, with mixed aerobic and anaerobic organisms. The principal risk factors for postcesarean endometritis are low socioeconomic status, extended duration of labor and ruptured membranes, multiple vaginal examinations, internal fetal monitoring, and pre-existing vaginal infections (principally, bacterial vaginosis and group B streptococcal colonization).
Two interventions are clearly of value in reducing the incidence of endometritis: administration of prophylactic antibiotics prior to the surgical incision and removal of the placenta by traction on the cord as opposed to manual extraction.5,6
The assessment by Caissutti and colleagues confirms that a third measure — preoperative vaginal cleansing — also helps reduce the incidence of postcesarean endometritis. The principal benefit is seen in women who have been in labor with ruptured membranes, although certainly it is not harmful in lower-risk patients. The intervention is simple and straightforward: a 30-second vaginal wash with a povidone-iodine solution just prior to surgery.
WHAT THIS EVIDENCE MEANS FOR PRACTICE
From my perspective, the interesting unanswered question is why a chlorhexidine solution with low alcohol content was not more effective than povidone-iodine, given that a chlorhexidine abdominal wash is superior to povidone-iodine in preventing wound infection after cesarean delivery.7 Until additional studies confirm the effectiveness of vaginal cleansing with chlorhexidine, I recommend the routine use of the povidone-iodine solution in all women having CD.