Effects of cumulative prenatal substance exposure and environmental risks on children's developmental trajectories.

Examined the effects of cumulative prenatal substance exposure and cumulative environmental risk on the developmental trajectories of 278 infants, toddlers, and preschool children. Results indicated that both cumulative risk indexes were significantly correlated. Results also indicated that both indexes were related to decrements in developmental trajectories (intercept and slope) from 3 to 57 months of age. Both prenatal exposure and environmental risk added unique variance to the prediction of developmental level and rate of growth when entered after covariates (i.e., birth weight and sex). However, across a number of models with and without covariates, environmental risk accounted for more variance in developmental trajectories than did prenatal exposure. Implications are discussed.