Objective. To examine the relationship between maternal cigarette smoking during pregnancy and children's intellectual functioning during the first 4 years of life.
Design. Prospective follow-up of participants in a randomized trial of pregnancy and infancy nurse home visitation.
Setting. Semirural community in Upstate New York.
Participants. 400 families in which the mothers registered before the 30th week of pregnancy and had no previous live births. Eighty-five percent of the mothers were either teenagers (<19 years at registration), unmarried, or poor. Analysis limited to whites who comprised 89% of the sample.
Main results. Children in the comparison group whose mothers smoked 10 or more cigarettes per day during pregnancy had Stanford-Binet scores at 3 and 4 years of age that were 4.35 (95% CI: 0.02, 8.68) points lower (after controlling for a wide range of variables) than their counterparts whose mothers did not smoke during pregnancy.
Conclusions. The results of this study add to the increasingly consistent evidence that maternal cigarette smoking during pregnancy poses a unique risk for neurodevelopmental impairment among children and provide an additional reason for pregnant women not to smoke cigarettes.