Clindamycin for vaginosis reduces prematurity and late miscarriage
The Journal of Family Practice. 2003 August;52(8):587-604
August 1, 2003|The Journal of Family Practice
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- BACKGROUND: Bacterial vaginosis is associated with premature delivery and late miscarriage. In 2 previous randomized controlled trials, metronidazole did not reduce preterm delivery in low-risk pregnancies when used to treat bacterial vaginosis at 23 to 24 weeks estimated gestational age. Another randomized controlled trial showed an 18% absolute risk reduction in premature deliveries when metronidazole and erythromycin were used to treat bacterial vaginosis in pregnant women with preexisting risk factors for premature delivery.1
- POPULATION STUDIED: This British, 2-center study enrolled 6120 of 11,189 pregnant women in their early second trimester—between 12 and 22 weeks estimated gestational age—who agreed to screening for bacterial vaginosis or abnormal vaginal flora. Slides were gram-stained, and 2 independent investigators assessed the slides with the Nugent scoring system (0–10).
- STUDY DESIGN AND VALIDITY: The 494 women who met diagnostic criteria for bacterial vaginosis or abnormal vaginal flora were randomly assigned by computer to receive either clindamycin 300 mg orally twice daily for 5 days or matching placebo. Allocation was concealed, and the study was double-blinded.
- OUTCOMES MEASURED: The primary endpoint of the study was the number of late miscarriages (between 13 and 24 weeks gestation) and preterm deliveries (between 24 weeks and 37 weeks gestation). Secondary outcomes included admission to neonatal intensive care unit, birth weight, and number of weeks gestation at delivery.
- RESULTS: Women treated with clindamycin had a statistically significant reduced rate of late miscarriages or spontaneous preterm deliveries compared with women in the placebo group (5.3% vs 15.8%). Ten (95% confidence interval, 6–20) women positive for bacterial vaginosis would need to be treated to prevent 1 late miscarriage or preterm delivery.
PRACTICE RECOMMENDATIONS
Using oral clindamycin to treat women with asymptomatic bacterial vaginosis during their second trimester (between 12 and 22 weeks estimated gestational age) reduces the number of premature births and late miscarriages. The study did not demonstrate a difference in the number of neonatal intensive care unit admissions, mean birth weight, or gestational age.
This is the first study demonstrating benefits in treating asymptomatic bacterial vaginosis early in pregnancy. It still needs to be determined, in larger trials, whether generalized screening and treatment for asymptomatic bacterial vaginosis in the early second trimester is beneficial and cost-effective.
