While we are not aware of research on the effects of the reproductive state of pregnancy on alcohol metabolism in women, per se, there is some evidence from a population-based, case-control study in Norway that variation in alcohol metabolism during pregnancy, as indicated by the ADH1C haplotypes of both the mother and child, is linked to an increased risk of oral cleft malformations in infants (227). Specifically, babies whose mothers engaged in heavy, intense drinking (consuming five or more drinks in one sitting) during the first trimester of pregnancy were more likely to develop oral clefts. The increased risk was only evident when either the mother or the baby carried the ADH1C haplotype associated with reduced alcohol-to-acetaldehyde metabolism, pointing to ethanol (more than acetaldehyde) as the teratogen for this specific birth defect.
