Quantification of corticosteroid binding globulin by electroimmunoassay during human pregnancy.

Corticosteroid binding globulin (CBG) was purified by one step positive immunospecific affinity chromatography and antibody to human CBG produced in goats. The goat anti-human CBG was used in the development of a precise rocket immunoelectrophoresis for CBG quantification. CBG levels measured by this assay were found to increase from 30 AU/ml to 100 AU/ml during pregnancy. There was no statistically significant association observed between levels of CBG, or circulating estriol, or pregnancy zone protein. Circulating CBG was estimated in 32 women with pregnancy associated hypertension, the levels were all within the normal range, and not significantly different from those seen in matched controls.