Prenatal exposure to alcohol is one of the leading preventable causes of birth defects, mental retardation, and neurodevelopmental disorders in the United States. One of the national health objectives for 2010 is to increase to 94% the percentage of pregnant women abstaining from alcohol use [corrected]. During 1991-1995, alcohol use by pregnant women increased substantially, and alcohol use by nonpregnant women of childbearing age increased slightly. To characterize trends in alcohol use among women of childbearing age, CDC analyzed representative survey data from the Behavioral Risk Factor Surveillance System (BRFSS) during 1991-1999. This report summarizes the results of the analysis, which indicate that the rate of any alcohol use (i.e., at least one drink) during pregnancy has declined since 1995. However, rates of binge drinking (i.e., > or = 5 drinks on any one occasion) and frequent drinking (i.e., > or = 7 drinks per week or > or = 5 drinks on any one occasion) during pregnancy have not declined among nonpregnant women of childbearing age. Health-care providers should routinely screen women of childbearing age for alcohol use and counsel them about the adverse effects of alcohol use during pregnancy.