We selected 10 candidate polymorphisms in four ADH genes and found evidence for a strong inverse association between the A allele of the non-synonymous variant rs1229984 in ADH1B and alcohol drinking before pregnancy and binge drinking patterns during pregnancy. Further analyses suggested a role for this variant in predicting drinking cessation particularly in the first trimester. Since the strongest predictor of drinking cessation during pregnancy is alcohol consumption before pregnancy (34,35), we repeated the analyses adjusting for this covariate potentially on the causal pathway, and the evidence remained strong, although there is a small chance that this could still be due to residual confounding, i.e. our inability to capture drinking behaviors with more precision.
