Vaginal clindamycin in preventing preterm birth and peripartal infections in asymptomatic women with bacterial vaginosis: A randomized, controlled trial

Objective: To determine whether treatment of bacterial vaginosis (BV) in ea rly pregnancy decreases the risk of preterm delivery and peripartum infecti ous morbidity. Methods: In this multicenter, randomized, double-masked, placebo-controlled intervention trial, screening for BV was performed by vaginal Gram stain o btained from 5432 healthy women with singleton pregnancies during the first antenatal clinic visit at 10-17 weeks' gestation. Bacterial vaginosis-posi tive women with no past history of preterm delivery were randomized to a si ngle course of treatment with either 2% vaginal clindamycin cream or identi cal placebo cream for 7 days. Repeat Cram stains were taken 1 week after tr eatment and at 30-36 weeks' gestation. Preterm delivery was defined as spon taneous delivery before 37 gestational weeks. Peripartum infectious morbidi ty was defined as postpartum endometritis, postpartum sepsis, postcesarean wound infection, or episiotomy wound infection, necessitating antimicrobial therapy. According to the power analysis, 180 patients were needed for bot h treatment arms to show a three-fold difference in the rates of preterm bi rths. Results: The overall prevalence of BV was 10.4%. Of all BV-positive women, 375 (66%) were randomized to the treatment arms. The primary cure rate was 66% in the clindamycin group; in the placebo group, 34% spontaneously clear ed BV (odds ratio [OR] 1.9, 95% confidence interval [CI] 1.3, 2.8). The rat e of preterm deliveries was 5% in the clindamycin group and 4% in the place bo group (OR 1.3, 95% CI 0.5, 3.5). The rate of peripartum infectious morbi dity was 11% in the clindamycin group and 18% in the placebo group (OR 1.6, 95% CI 0.9, 2.8). Bacterial vaginosis recurred in 7% of women. The rate of preterm deliveries was 15% in this subgroup compared with 2% among women w ho remained BV negative (OR 9.3, 95% CI 1.6, 53.5). Conclusion: Vaginal clindamycin did not decrease the rate of preterm delive ries or peripartum infections, but recurrent or persistent BV increased the risk for these complications. (Obstet Gynecol 2001;97:643-8. (C) 2001 by T he American College of Obstetricians and Gynecologists.).