BackgroundPatterns of smoking vary as a function of age and race. The goals of this study were to identify trajectories of maternal cigarette use over a 17-year span, and to determine if maternal age at first birth and race were associated with smoking trajectories. MethodsPregnant women (N=690) were recruited at an urban prenatal clinic. The women (13–42years old; 62% African-American, 38% White) were interviewed about cigarette use during pregnancy and 6, 10, 14, and 16years postpartum. Growth mixture modeling (GMM) was used to identify trajectories. Regressions were used to determine if maternal age at first birth and race predicted trajectory class membership. ResultsA GMM of maternal cigarette use delineated 5 groups: none/unlikely to use (33%), decreasing likelihood of use (6%), late desistance (5%), increasing likelihood of use (17%), and chronic use (39%). Women who became mothers at a younger age were more likely to be classified as late desisters or increasingly likely to smoke. White mothers were more likely to be chronic smokers. Different smoking trajectories and predictors of trajectories were identified for the African-American and White mothers. Covariates including prenatal substance use, hostility, education, and economic hardship also differentiated smoking trajectories. ConclusionsBoth prevention and treatment of smoking should be targeted to specific groups by age of first pregnancy and race. Pregnant smokers should be provided with more information and resources to help them avoid cigarettes during pregnancy and maintain abstinence after pregnancy.