Prenatal alcohol exposure and language delay in 2-year-old children: the importance of dose and timing on risk

Abstract

Objective: The aim of this study was to investigate the association of dose and timing of prenatal alcohol exposure with early language acquisition.

Methods: We examined language delay in a randomly selected, population-based sample of Western Australian children born in 1995-1996 whose mothers had agreed to participate in a longitudinal study on health-related behaviors and who had completed the 2-year questionnaire (N = 1739). Information on alcohol consumption was collected at 3 months after birth for four periods; the three months pre-pregnancy and for each trimester separately. Prenatal alcohol exposure was grouped into none, low, moderate-heavy and binge (>5) based on the total quantity consumed per week, quantity consumed per occasion, and frequency of consumption. The communication scale from the Ages & Stages Questionnaire was used to evaluate language delay. Logistic regression analysis was used to generate odds ratios and 95% confidence intervals, adjusted for confounding factors.

Results: There was no association between low levels of alcohol consumption and language delay at any time period, although there was a nonsignificant 30% increase in risk when moderate-to-heavy levels of alcohol were consumed in the third trimester. Children exposed to a binge pattern of maternal alcohol consumption in the second trimester had nonsignificant, three-fold increased odds of language delay, with a similar estimate following third trimester alcohol exposure after controlling for covariates.

Conclusions: This study did not detect an association between low levels of prenatal alcohol exposure and language delay when compared with women who abstained from alcohol during pregnancy. A nonsignificant threefold increase in the likelihood of language delay was seen in children whose mothers binged during late pregnancy. However, the small numbers of women with a binge-drinking pattern in late pregnancy limited the power of this study; studies analyzing larger numbers of children exposed to binge drinking in late pregnancy are needed.