The outcome of pregnancy was studied in 2,403 girls who received their care at the Chicago Board of Health and were 15 years of age or under at the time of conception. This was compared to the outcome of pregnancy in 4,400 girls of the same age group who had not received care at the Chicago Board of Health. Some of these patients received private care, some clinic care, and some had no prenatal care at all. The comparison was made in respect to hebdomadal and neonatal mortality, prematurity, and those conditions leading to infant mortality which had direct relationship to obstetric care. The study also included the incidence of complications both prenatal and intrapartum. The study revealed that the hebdomadal mortality rate was 92 per cent higher and the neonatal mortality rate was 94 per cent higher in the patients who did not receive prenatal care at the Chicago Board of Health clinics. Other findings were significantly lower in those patients who had received their care at the Chicago Board of Health clinics. © 1969.