Incidence and quantitation of pregnancy-associated globulin in the Japanese.

It has been pointed out that a serum protein specific for pregnancy (pregnancy-associated globulin, PAG) appears in females near term and is maintained during some period after delivery. The incidence and quantitation of PAG in 120 pregnant females and normal subjects, 1,469 males and 355 females, were studied by double diffusion and single radial immunodiffusion methods. All the pregnant females were proved to have PAG. The incidence of PAG in normal males and in females over 16 years of age was 5.3% and 36.9%, respectively. In the females, the incidence of PAG tended to increase with aging; 63% over 31 years of age and 100% over 51 years. Quantitative analyses, which were expressed as a percentage of the pooled pregnant sera, showed that PAG OF pregnant sera ranged from 24 to 240 and that of normal sera from 1 to 33.