According to the study, people tend to adjust behaviors across their life-spans as they adopt new roles, such as marriage or parenting, that are incompatible with prior behaviors. The transition to parenthood appears to be particularly relevant for women, leading to a reduction in alcohol consumption. This study of maternal alcohol use is the first to focus on age at transition to motherhood as a predictor of trajectories of risky drinking during a 17-year span. Researchers recruited 456 pregnant women, ages 13 to 42 years, at an urban prenatal clinic. The women (64 percent African-American, 36 percent White) were interviewed about alcohol use during pregnancy, at delivery, and again at six, 10, 14, and 16 years postpartum. The majority of mothers (66 percent) were identified as having low-risk trajectories of alcohol use during the 17-year span. However, maternal age at first birth predicted one high-risk group: younger mothers were more likely to engage in risky drinking early in pregnancy, which continued for six to 14 years postpartum. The authors suggest that these results can help physicians target mothers who are likely to exceed national guidelines calling for abstinence during pregnancy, and no more than seven drinks per week during postpartum.