Prenatal alcohol exposure and gender differences in childhood mental health problems: a longitudinal population-based study.

OBJECTIVES: High levels of alcohol use during pregnancy can lead to adverse physical and neurodevelopmental outcomes in children. It remains uncertain whether there is a safe level of drinking during pregnancy. In this study we investigate whether very low levels of alcohol consumption (<1 drink per week) are independently associated with childhood mental health problems (assessed at 3 time points between ages 4 and 8 years) and whether these effects are moderated by gender. We expected that only higher levels of alcohol consumption would be associated with later mental health problems and that any associations might be more readily detectable in boys.
METHODS: This prospective, population-based study used data from the Avon Longitudinal Study of Parents and Children. We investigated the relationship between self-reports of the amount and frequency of alcohol use in the first trimester and the presence of clinically significant mental health (behavioral and emotional) problems at 47 and 81 months (parental report: n = 9086 and 8046, respectively) and at 93 to 108 months (teacher report: n = 5648).
RESULTS: After controlling for a range of prenatal and postnatal factors, the consumption of <1 drink per week during the first trimester was independently associated with clinically significant mental health problems in girls at 47 months. This gender-specific association persisted at 81 months and was confirmed by later teacher ratings.
CONCLUSIONS: Very low levels of alcohol consumption during early pregnancy may have a negative and persistent effect on mental health outcomes. Given the lack of a clear dose-response relationship and unexpected gender effects, these findings should be considered preliminary and need additional investigation.