Pregnant women who drink alcohol may be damaging the future fertility of their unborn sons, according to new research presented June 29 at an annual meeting of the European Society of Human Reproduction and Embryology in Rome. In the study, carried out in Denmark, doctors found that if mothers had drank 4.5 or more drinks a week while pregnant, then the sperm concentration of their sons, measured about 20 years later, was a third lower in comparison to men who were not exposed to alcohol while in the womb. A drink was measured as 12 grams of alcohol, which is the equivalent to one beer or one small glass of wine.
"Our study shows that there is an association between drinking a moderate amount of alcohol (about four to five drinks a week) during pregnancy and lower sperm concentrations in sons. However... we cannot say for certain that the alcohol causes the lower sperm concentrations. It is possible that drinking alcohol during pregnancy has a harmful effect on the semen-producing tissue in the testes—and thereby on semen quality in later life—but our study is the first of its kind, and more research within this area is needed," says lead author Dr. Cecilia Ramlau-Hansen, senior researcher at the Department of Occupational Medicine, Aarhus University Hospital (Denmark) and clinical associate professor at the Department of Epidemiology, Institute of Public Health, University of Aarhus.
According to the March of Dimes, though most women are aware that heavy drinking during pregnancy can cause birth defects, many do not realize that moderate or even light drinking also may harm the fetus. As health experts point out, no level of alcohol use during pregnancy has been proven safe. March of Dimes recommendations call for pregnant women to abstain from drinking any alcohol, including beer, wine, wine coolers, and liquor, throughout their pregnancy and while breastfeeding.