Outcomes for 6 pregnant methadone-maintained opiate-dependent subjects in enhanced treatment were compared to those of 6 women receiving conventional methadone maintenance. Enhanced treatment consisted of weekly prenatal care, relapse prevention groups, thrice weekly urine toxicology screening with positive contingency awards for abstinence, and therapeutic child care during treatment visits in addition to treatment as usual. Treatment as usual included daily methadone, group counseling, and random urine toxicology screening. Study patients differed from the comparison group in three important ways, having fewer urine toxicology screens positive for illicit substances (59% vs. 76%), three times as many prenatal visits (8.8 vs. 2.7), and heavier infants (median birth weight, 2959 vs. 2344 grams). These results suggest that enhanced drug treatment can improve pregnancy outcome and, in particular, reduce low birth weight for this high-risk population.