Early detection of human chorionic gonadotropin in urine by simple immunoassays.

Data are presented to show that human chorionic gonadotropin (hCG) in urine can be detected early in pregnancy by simple immunoassays performed prior to or around the time of the expected but missed menstrual period. Differences between the use of simple immunoassays with urine and radioimmunoassays and radioreceptor assays with serum are discussed.