One major consequence of drinking alcohol during pregnancy is a serious condition called fetal alcohol syndrome (FAS). FAS is the leading cause of mental retardation. In addition, FAS is characterized by the following:
A less severe, but still detrimental form of fetal alcohol syndrome is a condition called fetal alcohol effects (FAE). FAE is present in a larger population of newborns in the US and is characterized by some physical or mental defects that can be directly attributed to alcohol use during pregnancy.
The full picture of FAS usually occurs in babies born to alcoholic mothers, or those who drink more than four to five drinks/day. Even light or moderate drinking can affect the developing fetus. Because no amount of alcohol is safe, the US Surgeon General recommends that pregnant women avoid alcohol during pregnancy.