DESCRIPTION: Update of the 2001 U.S. Preventive Services Task Force (USPSTF) recommendation on screening for bacterial vaginosis in pregnancy. METHODS: The USPSTF weighed the benefits and harms of screening for bacterial vaginosis in pregnancy by identifying new evidence addressing previously identified gaps from the 2001 USPSTF recommendation. Published literature on this topic was identified by using MEDLINE, Cochrane Library databases, the Database of Abstracts of Reviews of Effects, reference lists, and consultation with experts and was systematically reviewed. When data allowed, a series of meta-analyses (using new and 2001 report data) was done to estimate the pooled effect of treatment on preterm delivery (<37 weeks, <34 weeks, or <32 weeks) and on low birthweight and preterm, premature rupture of membranes. RECOMMENDATION: Do not screen for bacterial vaginosis in pregnant women at low risk for preterm delivery. (D recommendation) RECOMMENDATION: Current evidence is insufficient to assess the balance of benefits and harms of screening for bacterial vaginosis in pregnant women at high risk for preterm delivery. (I statement).