Childhood Height and Weight Trajectories of Alcohol Exposed Infants in Utero: a Prospective Cohort Study
METHODS: We examined the association between maternal alcohol use during pregnancy and trajectories of offspring weight and height from 0-10 years in 7,597 women in the Avon Longitudinal Study of Parents and Children. Height and weight at birth, 3 months, 1, 3, 7 and 10 years was predicted for all individuals using linear spline multilevel models. To strengthen the inference that can be made from our results, we adjusted for measured confounders and compared maternal alcohol use with partner alcohol use during the woman's pregnancy, which is an approach that can partially control for unmeasured confounding.
RESULTS: Maternal occasional or light daily drinking during pregnancy was not associated with reduced birth weight or length or adverse growth trajectories up to age 10 in offspring. The infants of maternal heavy drinkers were born 0.78cm shorter -0.78 (95% CI -1.34, -0.22) and 0.22 kg lighter -0.22 (95% CI -0.34, -0.09) than infants of pregnancy abstainers but these differences were overcome with age such that offspring of maternal heavy drinkers were 0.59cm taller 0.59 (95% CI -0.93, 2.11) and 0.41 kg heavier 0.41 (95% CI -0.70, 1.52) by age 10. These associations were not observed for heavy partner drinking.
CONCLUSIONS: Maternal occasional or light daily drinking is not associated with birth weight, birth length or postnatal growth up to age 10, but residual confounding may be masking harmful effects. Maternal heavy drinking appears to have an intrauterine effect on reduced offspring birth weight and length that is overcome during childhood.