Prenatal alcohol exposure and infant behavior: immediate effects and implications for later development.

Infants exposed to alcohol prenatally, even when they do not suffer from fetal alcohol syndrome (FAS), may be at high risk for many of the negative outcomes typically found among children of alcoholics including hyperactivity and other behavioral and learning problems. A series of studies are described designed to investigate the incidence and persistence of central nervous system (CNS) related behavioral alterations in three groups of infants born to low SES black women: (1) those who never drank in pregnancy; (2) those who drank at an average of 12 ounces of absolute alcohol (AA) per week throughout pregnancy; and (3) those who drank an equivalent amount but stopped by the second trimester of pregnancy. Only healthy, full-term infants were examined for the physical dysmorphic features associated with FAS and for behavioral alterations that could be assessed using the Brazelton Neonatal Behavioral Assessment Scale. One hundred and three neonates were examined at three days; those who had been exposed to alcohol were found to be less optimal in neurobehavioral responses. Infants whose mothers continued to drink were significantly lower on their orientation toward auditory and visual stimuli, motor performance, and autonomic regulation than the nonexposed infants. Although a second study found that some of these effects were related to neonatal withdrawal syndrome, a follow-up to 30 days of age in a subsample of the original group found that there were persistent behavioral alterations. Infants in the stopped-drinking group showed more recovery over the first month than did those in the continued-drinking group in reflexive behavior and autonomic control. A reassessment at six months of 60 of the infants who had been tested at three days indicated that differences in orientation, motor performance, reflexive behavior and autonomic control were predictive of mental and motor performance on the Bayley Scales of Infant Development. This series of studies supports the contention that the negative effects on infant behavior of prenatal alcohol exposure are both immediate and persistent.