IMMUNOLOGICAL AND BIOLOGICAL ACTIVITY OF HUMAN CHORIONIC GONADOTROPHIN IN URINE AND SERUM OF PREGNANT WOMEN AND WOMEN WITH A HYDATIDIFORM MOLE
ABSTRACT When human chorionic gonadotrophin from the urine of pregnant women is assayed both biologically and immunologically, the ratio (B/I) between the two activities is less than unity, and changes as pregnancy progresses. This suggests that the two methods do not wholly measure the same activity. Urines from women with a hydatidiform mole have a B/I ratio higher than urines from women with normal pregnancies, and this difference can be used to distinguish between a pregnancy and a hydatidiform mole. The B/I ratio of the serum from pregnant women is significantly higher than that of the urine. The B/I ratio of serum from women with a hydatidiform mole, and from those with a normal pregnancy, are of the same magnitude. Factors which might influence the immunological and biological HCG activity in the urine and serum are discussed.