Assessing the impact of maternal drinking during and after pregnancy

Recent findings from longitudinal followup studies of adolescents and adults with fetal alcohol syndrome (FAS) indicate that the deficits associated with this disorder are long lasting and pervasive. In addition, followup data from several large, prospective studies of cohorts representing a broad range of alcohol exposure levels have confirmed that although FAS represents the severe end of a continuum of birth defects, moderate' levels of alcohol intake produce physical and neurobehavioral deficits that are similar to, but less severe than, FAS (e.g., Streissguth et al. 1986, 1994; Coles et al. 1991; Jacobson and Jacobson 1994; Goldschmidt et al. 1996). Accumulating evidence shows that many FAS deficits can be detected at infancy and remain through adolescence into adulthood. In particular, an abnormally small head circumference (i.e., microcephaly) and intellectual problems persist as an affected child matures, whereas behavioral, emotional, and social problems can become more pronounced (e.g., Streissguth et al. 1991). In addition, the long-term clinical consequences in terms of psychopathology and social maladjustment are only recently being recognized and persist even in people with FAS who were raised in a stable, supportive environment (Steinhausen et al. 1993). Incidences of maladaptive behaviors, such as poor judgment, failure to consider the consequences of one's actions, and difficulty perceiving social cues, are common, as are legal problems resulting from sexual misconduct, drunk driving, shoplifting, and other socially inappropriate behaviors (LaDue et al. 1992). In a recent long-term followup study of a Seattle cohort of adolescents and adults with FAS, Streissguth and colleagues (1996) distinguished between prenatal, or "primary," disabilities, which reflect central nervous system (CNS) dysfunctions inherent in the FAS diagnosis, and "secondary" disabilities, with which a person is not born and which presumably could be ameliorated through intervention. Examples of secondary disabilities include mental health problems, disrupted schooling (e.g., dropping out or being suspended or expelled), trouble with the law (e.g., being charged with or convicted of a crime), inappropriate sexual behavior (e.g., promiscuity), alcohol or drug problems, dependent living as an adult (e.g., an inability to manage money), and problems with employment (e.g., trouble holding a job). Streissguth and colleagues concluded that legal problems and other secondary disabilities occur frequently in adolescents and adults with FAS, with incidences ranging from approximately 30 to 94 percent for various types of secondary disabilities among the study sample. Prenatal Versus Postnatal Effects This article aims to demonstrate the need to differentiate the impact of prenatal drinking from the impact of the environment in which the child is raised when assessing neurobehavioral and other outcomes in children whose mothers drank both during and after pregnancy. In the 20 years since FAS was first identified, a major body of research has been compiled on the effects of prenatal alcohol exposure as well as the impact of being raised by an alcoholic2 parent. Distinguishing between the effects of prenatal exposure and the effects of postnatal environment often presents a major methodological challenge to researchers, however, because women frequently drink both during and after pregnancy (i.e., prenatal and postnatal drinking are moderately related). An association between drinking during pregnancy and neurobehavioral function in infants and children normally is interpreted as teratogenic (i.e., attributable to a direct effect of alcohol exposure on fetal CNS development). The specific body systems affected by alcohol exposure and the resultant outcomes depend on when exposure occurs during the prolonged period of CNS sensitivity to alcohol (see figure 1). For example, first-trimester exposure is related to craniofacial anomalies (e. …