The relationship between weight gain and nutrition in pregnancy.

Balanced nutrition and weight gain during pregnancy, and the relationship between these variables and pregnancy outcomes were examined. Data were collected from 510 pregnant women and from their prenatal, hospital, and infants' health records. Despite a common assumption in the prenatal literature that weight gain during pregnancy reflects nutritional adequacy, nutrition and weight gain were only weakly related in this sample. Further, nutritional balance did not significantly contribute to additional explained variance in mother's weight gain when gestation, body mass index, and edema were controlled. Moreover, it was weight gain, not nutrition, that contributed to variance in baby's birth weight. These results suggest that while weight gain during pregnancy influences fetal outcomes, weight gain may not be a valid measure of nutrition.