Pregnancy weight gain in adolescents and young adults.

We examined whether adolescents required greater prenatal weight gains than nonadolescents to deliver equal weight babies following a low-risk pregnancy. Maternal characteristics and monthly weight gains were collected from medical records obtained from a private health maintenance organization (n = 423). Maternal weight gain, gestational age, parity, and cigarette use during pregnancy were significant predictors of infant birth weight in our regression models. Subjects were nonsmokers with a gestational age greater than 37 weeks and a parity equal to 0 who entered prenatal care during the first trimester of pregnancy. Mean total weight gains for the adolescents (16.2 +/- 4.8 kg; n = 51) and adults (15.2 +/- 5.4 kg; n = 65), and infant birth weights were similar. Mean infant birth weight was 3473 +/- 394 g for the adolescents and 3339 +/- 453 g for the young adults, whereas the optimal weight range for newborns is about 3500-3999 g. Modifiable risks are the important predictors of infant birth weight, and adolescents do not appear to require a greater weight gain than young adults to deliver similar weight babies.