Concentration of serum prealbumin and retinol-binding proteins during pregnancy.

Concentrations of the rapid-turnover plasma proteins prealbumin and retinol-binding protein are measured in nonpregnant subjects to detect subclinical malnutrition. In this study, blood samples were taken from 30 normal pregnant women to establish normative data on the concentrations of these two plasma proteins during pregnancy. Twenty-five normal adults were used as controls. Total protein and albumin were concomitantly measured and, as expected, the concentration of both decreased during pregnancy. In contrast, plasma concentrations of prealbumin and retinol-binding protein remained unchanged. Two malnourished pregnant women had low levels of both prealbumin and retinol-binding protein, which reverted to normal once adequate caloric and protein intake was established. These findings suggest that prealbumin and retinol-binding protein measurements may be used during pregnancy to detect malnutrition and monitor the effect of dietary therapy.