The association of mild, moderate, and binge prenatal alcohol exposure and child neuropsychological outcomes: a meta-analysis

Background: The objective of this review is to evaluate the literature on the association between mild, moderate, and binge prenatal alcohol exposure and child neurodevelopment.

Methods: Meta-analysis with systematic searches of MEDLINE (1970 through August 2012), EMBASE (1988 through August 2012), and PsycINFO(®) (1970 through August 2012) and examination of selected references.

Results: From 1,593 articles, we identified 34 presenting data from cohort studies that met our inclusion criteria. Information on study population, outcomes, measurement instruments, timing and quantification of alcohol exposure, covariates, and results was abstracted. Outcomes included academic performance, attention, behavior, cognition, language skills, memory, and visual and motor development. The quality of each article was assessed by 2 researchers using the Newcastle-Ottawa Scale. Based on 8 studies of 10,000 children aged 6 months through 14 years, we observed a significant detrimental association between any binge prenatal alcohol exposure and child cognition (Cohen's d [a standardized mean difference score] -0.13; 95% confidence interval [CI], -0.21, -0.05). Based on 3 high-quality studies of 11,900 children aged 9 months to 5 years, we observed a statistically significant detrimental association between moderate prenatal alcohol exposure and child behavior (Cohen's d -0.15; 95% CI, -0.28, -0.03). We observed a significant, albeit small, positive association between mild-to-moderate prenatal alcohol exposure and child cognition (Cohen's d 0.04; 95% CI, 0.00, 0.08), but the association was not significant after post hoc exclusion of 1 large study that assessed mild consumption nor was it significant when including only studies that assessed moderate alcohol consumption. None of the other completed meta-analyses resulted in statistically significant associations between mild, moderate, or binge prenatal alcohol exposure and child neuropsychological outcomes.

Conclusions: Our findings support previous findings suggesting the detrimental effects of prenatal binge drinking on child cognition. Prenatal alcohol exposure at levels less than daily drinking might be detrimentally associated with child behavior. The results of this review highlight the importance of abstaining from binge drinking during pregnancy and provide evidence that there is no known safe amount of alcohol to consume while pregnant.