A lower ratio of reduced to total albumin in serum is associated with protein nutritional status of pregnant women in Japan.

Protein-energy undernutrition is potentially prevalent among Japanese pregnant women, and biomarkers that objectively indicate the protein nutritional status during pregnancy may help in implementing appropriate protein supplementation to these women. We hypothesized that a serum parameter of pregnant women, the ratio of reduced to total albumin (reduced ALB ratio), would be associated with protein intake during pregnancy. The serum reduced ALB ratio of pregnant women was compared with protein intake and with gestation outcomes (gestation length and infant birth weight) in an observational study of 115 Japanese pregnant women. The serum reduced ALB ratio in the third trimester tended to be positively correlated with gestation length (P = .07). Infant birth weights tended to be different between protein intake tertiles (P = .09); the mean infant birth weight was higher in the third tertile compared with the first and second tertiles. The protein intake of pregnant women was significantly and positively correlated with the serum reduced ALB ratio in the second trimester. The serum reduced ALB ratio reflects protein nutritional status during pregnancy and may contribute to healthier gestation outcomes.