Effects of prenatal alcohol and cigarette exposure on offspring substance use in multiplex, alcohol-dependent families.

BACKGROUND: Prenatal exposures to alcohol, cigarettes, and other drugs of abuse are associated with numerous adverse consequences for affected offspring, including increased risk for substance use and abuse. However, maternal substance use during pregnancy appears to occur more often in those with a family history of alcohol dependence. Utilizing a sample that is enriched for familial alcohol dependence and includes controls selected for virtual absence of familial alcohol dependence could provide important information on the relative contribution of familial risk and prenatal exposures to offspring substance use.
METHODS: A sample of multigenerational families specifically ascertained to be at either high or low risk for developing alcohol dependence (AD) provided biological offspring for a longitudinal prospective study. High-risk families were selected based on the presence of 2 alcohol-dependent sisters. Low-risk families were selected on the basis of minimal first and second-degree relatives with AD. High-risk (HR = 99) and Low-risk offspring (LR = 110) were assessed annually during childhood and biennially in young adulthood regarding their alcohol, drug, and cigarette use. At the first childhood visit, mothers were interviewed concerning their prenatal use of substances.
RESULTS: High-risk mothers were more likely to use alcohol, cigarettes, and other drugs during pregnancy than low-risk control mothers, and to consume these substances in greater quantities. Across the sample, prenatal exposure to alcohol was associated with increased risk for both offspring cigarette use and substance use disorders (SUD), and prenatal cigarette exposure was associated with increased risk for offspring cigarette use. Controlling for risk status by examining patterns within the HR sample, prenatal cigarette exposure remained a specific predictor of offspring cigarette use, and prenatal alcohol exposure was specifically associated with increased risk for offspring SUD.
CONCLUSIONS: Women with a family history of SUD are at increased risk for substance use during pregnancy. Both familial loading for alcohol dependence and prenatal exposure to alcohol or cigarettes are important risk factors in the development of offspring substance use. An inadequate assessment of family history may obscure important interactions between familial risk and prenatal exposures on offspring outcomes.