Birth to age 7 growth of children prenatally exposed to drugs: a prospective cohort study

Prenatal exposure to cocaine, alcohol, and cigarettes has been linked to decreased birth weight and length. Unclear, however, is whether growth deficits persist into childhood. Women who were pregnant, African-American, not HIV-positive, and who delivered singleton infants were extensively screened throughout pregnancy for cocaine, alcohol, cigarette, and other illicit drug use. Of the approximately 1100 eligible subjects, 665 families were located at a 7-year postbirth follow-up and 540 participated. After appropriate control for potential confounders and prenatal exposures, prenatal exposure to cocaine, alcohol, and cigarettes each independently predicted birth weight and length. At age 7, prenatal cocaine exposure was significantly related to height deficits after accounting for other prenatal exposures and significant confounders. Children at age 7 exposed to cocaine in utero were up to 1 in. shorter and twice as likely to fall below the 10th percentile in height as the control children after accounting for other significant confounders including other prenatal exposures. Maternal age moderated the relation between prenatal exposures and child growth. Children born to women over 30 and exposed to cocaine were up to 2 in. shorter and four times more likely to have clinically significant height deficits at age 7. Children of older women and exposed to moderate-to-high levels of alcohol prenatally were up to 14 lb lighter and five times more likely to fall below the 10th percentile in weight. Similar growth restriction was not associated with prenatal exposures for children born to younger mothers. These outcomes add to the growing body of literature detailing long-term effects of prenatal drug exposure, suggesting differential effects for cocaine and alcohol, and indicating that maternal age may moderate these effects. Mechanisms for growth restriction and failure of catch-up under conditions of prenatal exposures are presented, suggesting further study of these developmental outcomes.