Fetal alcohol spectrum disorders: Extending the range of structural defects.

Although the structural phenotype of fetal alcohol syndrome (FAS) is established, prenatal exposure to alcohol may produce a broader spectrum of defects, fetal alcohol spectrum disorder (FASD). Documenting the full spectrum of defects associated with FASD is critical to determining the true incidence of this disorder. We examined 831 children from the Collaborative Initiative on Fetal Alcohol Spectrum Disorders using a structured protocol for diagnosis of FAS using the cardinal facial and growth features, and assessment of additional structural defects thought to occur more often in children with prenatal alcohol exposure. Subjects were classified as FAS, Deferred (some characteristic features of FAS), or No FAS, Groups were compared on prevalence of additional features and number of additional features observed, stratified by diagnostic category, sex, race, and age. Prevalence of most additional features was greatest among subjects with FAS and least among No FAS. A higher frequency of additional features was observed among FAS and Deferred subjects ≥12 years of age than among those under 12. FAS and Deferred Whites had greater frequency of additional features than Cape Colored. Prenatal alcohol exposure may produce a broad spectrum of structural defects that goes beyond FAS with implications regarding the impact of alcohol on the developing fetus, a prerequisite for ultimate prevention of FASD.