Adolescent age at first pregnancy and subsequent obesity.

Adolescent pregnancy has been associated with subsequent obesity. This paper examines the patterns of obesity for second and third pregnancies among women who had their first singleton pregnancy as teenagers. We used maternally-linked data from 1978 to 1990 among 43,160 Missouri resident women. Age, parity, interpregnancy interval and prior body mass index were significantly associated with subsequent obesity among adolescents. Race, marital status and smoking had significant interactions with age. Among older women, being African-American and never having married was associated with an increased probability of obesity, and smoking had a greater effect on obesity at higher maternal age. Race and marital status did not have significant effects on obesity among younger women. The most important predictor of obesity was prior body mass index. Body mass index before the first pregnancy had a greater effect on subsequent obesity if the intervening interpregnancy weight gains were large. Excessive weight gain during pregnancy presents the health care provider with a dilemma. An increase in birthweight associated with high prenatal weight gains may diminish the risk of infant mortality and morbidity in an index pregnancy, but subsequent obesity may increase perinatal mortality rates, the rates of obstetric problems and neural tube defects.