Prenatal exposure to alcohol is one of the leading preventable causes of birth defects, mental retardation, and neurodevelopmental disorders. In 1973, a cluster of birth defects resulting from prenatal alcohol exposure was recognized as a clinical entity called fetal alcohol syndrome. More recently, alcohol exposure in utero has been linked to a variety of other neurodevelopmental problems, and the terms alcohol-related neurodevelopmental disorder and alcohol-related birth defects have been proposed to identify infants so affected. This statement is an update of a previous statement by the American Academy of Pediatrics and reflects the current thinking about alcohol exposure in utero and the revised nosology.