Fetal alcohol syndrome is the term used to describe a pattern of abnormalities observed in children born to alcoholic mothers. Researchers originally postulated that malnutrition might be responsible for these defects; however, the pattern of malformation associated with FAS is not seen in children born to malnourished women, and alcohol has been found to be acutely toxic to the fetus independently of the effects of malnutrition. Mental handicaps and hyperactivity are probably the most debilitating aspects of FAS, and prenatal exposure to alcohol is one of the leading known causes of mental retardation in the Western World. From a scientific perspective, the link between moderate drinking and alcohol-related birth defects has not been clearly established. Whether there is a threshold below which alcohol can be consumed without harming the fetus is not known. Researchers are working on the development of an objective marker for alcohol consumption that will clarify this issue and assist clinicians in identifying alcohol-abusing patients as a part of routine prenatal care. Although some clinicians believe that recommending total abstention from alcohol for pregnant women may subject them to unwarranted guilt about drinking small amounts of alcohol, most accept the need for clinical caution. Because researchers do not know at what point alcohol damage occurs to the fetus, it is prudent to recommend that pregnant women abstain from alcohol use pending confirmation of alcohol's effect on fetal development. 28 references