In this prospective study of substance use during pregnancy, women were interviewed in their 4th and 7th prenatal months, and women and children were assessed at 24 hr, 8, 18, and 36 months post‐partum. Data are presented on the outcome of 519 children at age 3. At 3 years, children who were exposed prenatally to alcohol were smaller in weight, length, and head circumference. They also had an increased number of minor physical anomalies. These effects were found even after controlling for nutritional and environmental factors. The persistence of growth effects at age 3 suggests that children exposed to alcohol prenatally may have a diminished capacity for growt