human chorionic gonadotropin ( hcg ) in maternal serum was analyzed by a hcg-beta-subunit , radioimmunoassay ( hcg-beta-ria ) in 36 cases after induced first-trimester abortion , 35 cases of spontaneous abortion in the first trimester , and in 35 cases of ectopic pregnancy to determine the time between the apparent removal of all trophoblastic tissue by surgical intervention and the disappearance of hcg from the blood .
C0106132
hcg-beta-subunit
C0018062
hcg