After years of confusing and contradictory advice about alcohol consumption during pregnancy, a new study may have the final word: Just don’t drink. The study, published Wednesday in the journal PLoS ONE, reveals that even a few drinks a week by an expectant mother can lead to reductions in a child’s IQ if the child has certain genetic variations impairing their ability to break down alcohol.
Research into the effects of alcohol consumption during pregnancy has generally focused on heavy drinking, and the resulting incidence of fetal alcohol syndrome. Meanwhile, observational studies of moderate drinking have shown little negative effect. As a result, many physicians advise their expectant patients that a drink every now and then is fine, so long as the drinking never becomes heavy.
The new report specifically looked at mothers who consumed between one and six drinks a week. As an added layer, the researchers also analyzed the DNA of the children to look for differences in the parts of the genetic code responsible for breaking down alcohol — an important consideration that can drastically change the effect of a drink on the body.
By using a biological variable to ask whether small doses of alcohol have the potential to cause harm, the researchers eliminated concerns about sociological or socioeconomic differences between abstainers and drinkers.