Dietary protein in pregnancy: effect on anthropometric indices of the newborn infant

The urinary urea nitrogen/creatinine nitrogen ratio (UN/CN), an objective index of the level of dietary protein, was measured serially throughout pregnancy in 870 women. The mean UN/CN ratio was calculated for each subject. Subjects were grouped by mean UN/CN ratios. Those in the lowest decile (mean protein intake, 0.7 gm/kg/day) in comparison with those in the highest decile (mean protein intake, 1.5 gm/kg/day) were of lower socioeconomic class, weighed more before pregnancy, and gained less during pregnancy. However, birth weight and other anthropometric indices of the newborn infant were not related to the level of dietary protein during pregnancy.