Prenatal alcohol, marijuana, and tobacco use: infant mental and motor development.

These data are from a longitudinal study of prenatal alcohol and marijuana use in a low income sample. Half of the women were black and half were white. Women who used alcohol and/or marijuana during their pregnancies were light to moderate users; most decreased or discontinued their use after the first trimester. At the first follow-up phase, which occurred at a median age of 9 months, the children were functioning above average on the Bayley Scales of Infant Development (BSID). Prenatal alcohol and tobacco use did not predict BSID mental or motor scores at this phase. Third trimester marijuana use was associated with decreased BSID mental scores. Age at assessment was the most important predictor at this phase. The second follow-up occurred at a median age of 19 months when the group means for the BSID were lower. Prenatal alcohol and marijuana use did not predict outcome at this phase. Prenatal and current cigarette use were associated with decreased BSID mental scores. Demographic and environmental variables were important predictors at this phase.