Characterizing the role of early alcohol reexposure in associations of prenatal alcohol exposure with adolescent alcohol outcomes

Background Prenatal alcohol exposure has been linked to a host of negative outcomes, although it is largely unknown whether prenatal exposure leads to an earlier age of initiation of alcohol use or exacerbates early alcohol initiation. The current study examined whether adolescents exposed to heavy drinking during gestation began drinking earlier than their nonexposed peers and whether an earlier age of alcohol reexposure in adolescence exacerbated associations with adverse alcohol outcomes. Methods Adolescents (17 years of age; 57% female; 96% White) from a longitudinal, population-based cohort study, the Avon Longitudinal Study of Parents and Children, reported on the age they first consumed a whole drink and other alcohol behaviors. Adolescents' mothers also reported on their own heavy drinking during pregnancy (i.e., any consumption of 4+ U.K. units in a drinking day at either 18 or 32 weeks of gestation). Results Survival analyses indicated that prenatal heavy drinking exposure was not associated with an earlier initiation of alcohol use after controlling for potential demographic and parental mental health and substance use confounds. Generalized negative binomial models demonstrated that prenatal heavy drinking exposure moderated associations of the age of alcohol initiation with alcohol quantity and heavy drinking frequency (but not alcohol frequency or Alcohol Use Disorders Identification Test score), after controlling for the same demographic and parental confounds. Specifically, earlier alcohol initiation was associated with more adverse alcohol outcomes regardless of prenatal exposure. However, the protective associations of delayed alcohol initiation were lower among adolescents exposed to prenatal heavy drinking. Conclusions This study provides evidence for the interplay between prenatal and postnatal alcohol exposures. Importantly, adolescents who were prenatally exposed to heavy drinking appeared to be less protected by later alcohol initiation than those who were not exposed in utero.