Inadequate weight gain among pregnant adolescents: risk factors and relationship to infant birth weight

OBJECTIVE: Our purpose was to identify behavioral markers for inadequate weight gain (< 20 pounds) during pregnancy among adolescents < 18 years old. STUDY DESIGN: A total of 337 adolescents who were delivered of a term infant at our institution between March 10, 1992, and November 28, 1994 participated in this study. A comprehensive structured interview conducted at the first prenatal visit elicited demographic information and behavioral risk factors. Maternal weights, reproductive history, evidence of sexually transmitted disease, and infant birth weight were extracted from medical records. Logistic regression and chi 2 analyses compared characteristics and infant birth weights between those who gained < 20 pounds with those who gained > or = 20 pounds. RESULTS: A total of 11.6% (39/337) of the total sample gained < 20 pounds during the pregnancy. Adolescents who gained < 20 pounds compared with > or = 20 pounds were delivered of significantly lighter (2942 gm vs 3392 gm) infants and were more likely to be delivered of infants weighing < 2500 gm (13% vs < 1%). Stepwise logistic regression revealed that adolescents who were battered (odds ratio 5.3) or had a sexually transmitted disease (odds ratio 2.3) or an unplanned pregnancy (odds ratio 8.1) were at increased risk for insufficient weight gain during pregnancy. CONCLUSION: Our data suggest that behavioral risk factors are important in the identification of adolescents at greatest risk for inadequate weight gain. Early identification during pregnancy is essential to modify nutritional practices and thus minimize poor obstetric outcomes.