Determinants of weight gain in pregnant adolescents.

Maternal weight gain is the most important modifiable determinant of infant birth weight. Effective intervention requires an understanding of the factors that influence the amount of weight women gain during pregnancy. We studied the dietary, health, and social habits of 141 poor, black, 12- to 19-year-old prenatal patients to learn more about the determinants of weight gain among pregnant adolescents. The patients were divided into three weight gain groups: slow (n = 23): less than 0.28 kg/week; average (n = 87): 0.28-0.45 kg/week; and rapid (n = 31): more than 0.45 kg/week. The results of logistic regression analysis revealed two statistically significant predictors of slow weight gain: the consumption of fewer than three snacks per day and delayed (third trimester) enrollment in the Supplemental Food Program for Women, Infants, and Children. By contrast, rapid gainers were more compliant with prenatal visits and reported more depressive symptoms and alcohol consumption than did other study subjects. We conclude that attention to these modifiable correlates of inadequate and excessive weight gain may enable dietitians and other health care providers to develop more effective strategies for promoting optimal weight gain among pregnant adolescents.