Rate and amount of weight gain during adolescent pregnancy: associations with maternal weight-for-height and birth weight.

This study presents information on the course and rates of weight gain and the associations among weight gain, prepregnancy weight-for-height, and infant birth weight, based on a total sample of 1419 uncomplicated term deliveries to adolescents. The distribution of cumulative weight gain indicates that for adolescents not only is the median gain at term (14.2-15.5 kg) significantly in excess of that reported for adults, but also weight-gain velocity is greater from the beginning of pregnancy. Although the contributions of prepregnancy weight-for-height and weight gain to birth weight may be independent, they are not necessarily additive. Birth weight does not appear improved for the infants of overweight adolescents except when weight gain is low (less than 11.1-12.3 kg at term), and, for Puerto Rican and black adolescents, birth weight is not further improved at any maternal prepregnancy body mass index (weight-for-height) with excessive weight gains (greater than 17.9-19.3 kg at term).