In utero alcohol exposure and prediction of alcohol disorders in early adulthood: a birth cohort study.

CONTEXT Little is known about the contribution of fetal alcohol exposure to the development of alcohol disorders in early adulthood. OBJECTIVE To examine the independent effect of maternal alcohol use during early vs late periods in pregnancy on the time of onset of alcohol disorders in offspring. DESIGN Follow-up study of the Mater-University of Queensland Study of Pregnancy and Its Outcomes (MUSP), a population-based birth cohort study commenced in Brisbane, Australia, in 1981 and designed to examine the association of maternal alcohol exposure with the onset of alcohol disorders. Mothers and children were followed up at birth, 6 months, and 5, 14, and 21 years after the initial interview. Maternal alcohol use was assessed before pregnancy, in early and late pregnancy, and at the 5- and 14-year follow-up visits. Alcohol disorders in early adulthood were assessed at age 21 years using the lifetime version of the Composite International Diagnostic Interview-computerized version. SETTING Population-based birth cohort study. PARTICIPANTS A subsample of 2138 participants for whom complete data were available at the 21-year follow-up. MAIN OUTCOME MEASURE Onset of alcohol disorder from adolescence to 21 years of age. RESULTS In utero alcohol exposure of 3 or more glasses was associated with alcohol disorders. The fully adjusted odds ratios (95% confidence intervals) of developing early-onset alcohol disorders at age 21 years were 2.95 (1.62-5.36) for those exposed to maternal drinking in early pregnancy and 1.35 (0.69-2.63) for those exposed in late pregnancy. There was also a strong association between alcohol exposure in early pregnancy and late-onset alcohol disorders (odds ratio, 3.29 [95% confidence interval, 1.74-6.24]). CONCLUSIONS Our results provide support for a biological origin of adult alcohol disorders and suggest that the association is not explained solely by maternal drinking or smoking during childhood and adolescence or other intervening factors. Further research is needed to understand the mechanisms underlying the association.