The effects of prenatal alcohol exposure.

Exposure to alcohol during gestation can cause persistent abnormalities in physical and cognitive development. Children who meet the clinical definition of fetal alcohol syndrome (FAS) are small for their age, exhibit characteristic facial anomalies, and demonstrate deficits in central nervous system development. Alcohol effects in children with prenatal exposure, but not FAS, are similar, although of smaller magnitude and not necessarily present in all three systems. The degree to which a person is affected by prenatal alcohol exposure depends on the amount, timing, and duration of the mother's alcohol consumption during pregnancy as well as maternal characteristics (e.g., age and comorbid psychiatric disorders) and environmental factors (e.g., socioeconomic status and family problems). Some exposure-related effects, such as growth deficits, are directly related to the amount of alcohol consumed, however, so that even a small amount of alcohol may affect child development. Therefore, the best policy continues to be abstinence during pregnancy. KEY WORDS: gestation; prenatal alcohol exposure; fetal alcohol effects; fetal alcohol syndrome; teratogens; congenital anomaly; fetal development; disorder definition; epidemiology; amount of AOD use; growth retardation; morphology; CNS function; mental retardation; cognitive development; demographic characteristics; psychosocial environment; literature review Pregnant alcoholic women risk the health of their offspring in multiple ways: (1) Exposure to alcohol during gestation may lead to fetal alcohol syndrome (FAS) or fetal alcohol effects; (2) the physical consequences of alcoholism in the mother (e.g., falls or malnutrition) may independently affect the developing fetus; (3) genetic vulnerability to alcoholism in the fetus may increase the effects of prenatal exposure; and (4) the lifestyle of an alcoholic parent may lead to negative consequences for the fetus, the pregnancy, and the developing child. This article addresses the first of these issues-the effects of exposure to alcohol during gestation-in detail. However, any or all of the other issues listed (i.e., concomitant genetic background and the physical and lifestyle deficits that accompany alcoholism) may exacerbate the adverse effects of prenatal alcohol exposure. As a teratogen, alcohol is capable of directly inducing developmental abnormalities in a fetus. Alcohol use during pregnancy is one of the most common known causes of preventable birth defects, and its results can persist as long-term deficits in physical and cognitive growth and development. The dangers of fetal alcohol exposure, initially identified in the late 1960's, are entirely preventable if women abstain from drinking during pregnancy. Given this fact, in 1981 the U.S. Surgeon General issued the first health advisory recommending that women who are pregnant or planning a pregnancy should not drink alcohol, and this advisory was repeated in 1990 and 1995. FAS DEFINITION AND DIAGNOSIS At the extreme end of the spectrum of prenatal exposure effects, FAS is a clinical diagnosis applied to children who have been exposed to alcohol during gestation and exhibit deficits in growth, physical structure (i.e., morphology), and the central nervous system (CNS). To meet the clinical case definition, the child must have symptoms in each of the following three categories: ( I) growth deficiency in both the prenatal and postnatal periods; (2) abnormalities in facial and skull structure, including small eye openings (i.e., short palpebral fissures), alterations in nose and forehead structure, an absent or elongated groove between the upper lip and nose (i.e., philtrum), a thin upper lip, a flattened midface, and underdevelopment of the upper or lower jaw; and (3) CNS deficits, such as mental retardation and behavioral problems (Sokol and Clarren 1989). Of these symptoms, the facial abnormalities are the most characteristic of FAS, whereas the CNS anomalies have the most significant effect on overall development. …