Previous animal and human studies have indicated that prenatal exposure to nicotine is associated with adverse reproductive outcomes, including altered neural structure and functioning, cognitive deficits, and behavior problems in the offspring. Our study extends previous research on humans by controlling a broad range of correlates of maternal smoking during pregnancy to determine if smoking is associated with behavior problems in the offspring severe enough to qualify for DSM-III-R diagnoses.
Subjects were 177 clinic-referred boys, ages 7 to 12 years at the time of the first assessment, who underwent longitudinal assessment for 6 years using annual structured diagnostic interviews. Correlates of maternal smoking during pregnancy and previously identified demographic, parental, perinatal, and family risk factors for the disruptive behavior disorders were controlled in logistic regression analyses.
Mothers who smoked more than half a pack of cigarettes daily during pregnancy were significantly more likely to have a child with conduct disorder (odds ratio, 4.4; P=.001) than mothers who did not smoke during pregnancy. This association was statistically significant when controlling for socioeconomic status, maternal age, parental antisocial personality, substance abuse during pregnancy, and maladaptive parenting.
Maternal smoking during pregnancy appears to be a robust independent risk factor for conduct disorder in male offspring. Maternal smoking during pregnancy may have direct adverse effects on the developing fetus or be a marker for a heretofore unmeasured characteristic of mothers that is of etiologic significance for conduct disorder.