THE INTRAVASCULAR MASS OF ALBUMIN DURING HUMAN-PREGNANCY - A SERIAL STUDY IN NORMAL AND DIABETIC WOMEN

Objective To quantify the changes in serum albumin during human pregna ncy. Design Longitudinal prospective study. Setting Before conception and antenatal clinic. Subjects Sixty-nine normal women and 23 women wi th Type 1 diabetes. Interventions Administration of Evans' blue dye an d collection of serum samples. Main outcome measures Albumin concentra tion, plasma volume and intravascular mass of albumin Results In norma l subjects serum albumin concentration showed a significant decrease o f 1.9 (95% CI 1.0 to 2.9) g/l by 7 weeks gestation with a further 8.2 (95 % CI 7.5 to 8.9) g/l decrease by 36 weeks gestation, an overall ch ange of 22%. Plasma volume first increased significantly by 190 (95% C I 105 to 275) ml between 7 and 12 weeks, with a further increase of 10 03 (95% CI 871 to 1135) ml between 12 and 36 weeks of pregnancy, a cha nge of 53%. The intravascular mass of albumin showed no change between non-pregnant, 7 and 12 week values but there was a significant rise o f 19.5 (95% CI 15.1 to 23.9) g between 12 and 28 weeks of gestation, a n overall increase of 19%. Diabetic subjects showed similar changes. C onclusions Rather than simply reflecting plasma volume dilution, the c hanges in serum albumin imply alterations in albumin metabolism during pregnancy.