Effect of paternal alcohol consumption before conception on infant birth weight. ALSPAC Study Team. Avon Longitudinal Study of Pregnancy and Childhood.

Previous studies of paternal drinking and fetal growth in both animals and human have produced conflicting results. We evaluated the association between paternal drinking before conception and infant birth weight in a cohort of 9,845 liveborn singleton infant born to couples who participated in the Avon Longitudinal Study of Pregnancy and Childhood (ALSPAC), ALSPAC is a population-based cohort study in which women and their partners completed several self-administered questionnaires over the course of pregnancy. Of participating male partners, 20% were reportedly daily drinkers before conception, and 8% were considered moderately heavy or very heavy drinkers. Because maternal drinking is highly correlated with paternal, the analyses were stratified by maternal drinking in early pregnancy. We also adjusted for confounders and known predictors of birth weight. For all three maternal drinking strata, all adjusted mean differences in birth weight across levels of paternal drinking were similar, and all had confidence intervals that included zero. These findings persisted even after adjustment for other covariates and after stratification by parental smoking, race, and education. The size of the ALSPAC cohort, the large number of heavy drinkers, and the availability of data from the fathers themselves support the conclusion that paternal drinking before conception is not an important predictor of infant birth weight in humans.