Background: A range of adverse birth outcomes is associated with heavy prenatal alcohol exposure.
Aim: To examine the effects of moderate levels of alcohol consumption during pregnancy on children's intellectual ability, learning and attention at 14 years of age.
Study design and subjects: The Mater-University of Queensland Study of Pregnancy involves a prospective birth cohort of 7223 singletons whose mothers were enrolled at the first antenatal visit. At 14 years, 5139 mothers and adolescents completed attentional and learning questionnaires, and 3731 adolescents completed psychometric assessments.
Outcome measures: For adolescents, the Wide Range Achievement Test--Revised (WRAT-R) and Raven's Standard Progressive Matrices Test (Raven's) were administered. Mothers completed the Child Behaviour Checklist (CBCL) and adolescents completed the Youth Self Report (YSR). Learning was assessed by a series of questions in the mother and adolescent questionnaires. Maternal measures included the quantity and frequency of alcohol consumption, and the extent of binge drinking.
Results: For consumption of <1 glass/day in early or late pregnancy, there was no association with any attention, learning or cognitive outcomes. The strongest estimates of effect were found among those consuming > or =1 glasses/day. Exposure in late pregnancy was associated with increased prevalence of overall learning difficulty in the unadjusted, although not the adjusted analysis. Binge drinking was associated with a higher prevalence of Raven's score <85 (1 standard deviation).
Conclusions: Although a number of study limitations need to be considered, the results suggest that consumption at the level of <1 drink/day does not lead to adverse outcomes in relation to attention, learning and cognitive abilities, as measured in the current research.