Adolescent pregnancy in Tasmania.

The obstetric performance of 1719 pregnancies in mothers aged less than 18 years was compared to that of the rest of the obstetric population. There was a significantly poorer outcome in the adolescents in the mean birthweight, the prevalence of birthweight below 2500 g and of gestation period below 28 weeks, Apgar score, perinatal mortality and the occurrence of hypertension in pregnancy. When the primiparous adolescent group (1607) was compared with primiparas aged 18-34 years (16 220), these differences were less marked. The two groups (adolescent and adult primiparas) were matched by marital status and socioeconomic class, and no significant differences were found in these parameters. It is concluded that biological age per se does not confer an increased risk in pregnancy. The high proportion of primiparas in the adolescent group (93%), and the associated increased prevalence of high-risk factors in this group (single marital status, low socioeconomic class, and smoking) would explain the poorer obstetric outcome in comparison with that of the total adult group.