Prenatal exposure to alcohol and its impact on reward processing and substance use in adulthood …this is the first study demonstrating that even moderate levels of alcohol drinking during pregnancy have long-lasting effects on brain function and risk of cannabis use in the offspring. Therefore, our study has critical implications for public health messaging on possible harms related to drinking during pregnancy.

Abstract: Heavy maternal alcohol drinking during pregnancy has been associated with altered neurodevelopment in the child but the effects of low-dose alcohol drinking are less clear and any potential safe level of alcohol use during pregnancy is not known. We evaluated the effects of prenatal alcohol on reward-related behavior and substance use in young adulthood and the potential sex differences therein…Maternal alcohol drinking was assessed during mid-pregnancy and pre-conception. Brain response to reward anticipation and reward feedback was measured using the Monetary Incentive Delay task and substance use in young adulthood was assessed using a self-report questionnaire. We showed that even a moderate exposure to alcohol in mid-pregnancy but not pre-conception was associated with robust effects on brain response to reward feedback (six frontal, one parietal, one temporal, and one occipital cluster) and with greater cannabis use in both men and women 30 years later. Moreover, mid-pregnancy but not pre-conception exposure to alcohol was associated with greater cannabis use in young adulthood and these effects were independent of maternal education and maternal depression during pregnancy. Further, the extent of cannabis use in the late 20 s was predicted by the brain response to reward feedback in three out of the nine prenatal alcohol-related clusters and these effects were independent of current alcohol use. Sex differences in the brain response to reward outcome emerged only during the no loss vs. loss contrast. Young adult men exposed to alcohol prenatally had significantly larger brain response to no loss vs. loss in the putamen and occipital region than women exposed to prenatal alcohol. Therefore, we conclude that even moderate exposure to alcohol prenatally has long-lasting effects on brain function during reward processing and risk of cannabis use in young adulthood.

Conclusions: Overall, our findings, based on 30 years’ worth of data on a prenatal birth cohort, suggest that even relatively moderate exposure to alcohol during pregnancy, a critical sensitive period for brain development, might alter neural reward processing in the offspring and contribute to the intergenerational transmission of risk for substance use disorders. This is the first prospective longitudinal study testing the impact of prenatal and pre-conception exposure to alcohol on brain response to reward processing and substance use in young adulthood. While a number of studies reported altered neurodevelopment and behavior in FASD, this is the first study demonstrating that even moderate levels of alcohol drinking during pregnancy have long-lasting effects on brain function and risk of cannabis use in the offspring. Therefore, our study has critical implications for public health messaging on possible harms related to drinking during pregnancy. (Sources: Translational Psychiatry (nature.com)