Human Chorionic Gonadotropin in Maternal Plasma After Induced Abortion, Spontaneous Abortion, and Removed Ectopic Pregnancy

Human chorionic gonadotropin (hCG) in maternal serum was analyzed by a hCG-β-subunit, radioimmunoassay (hCG-β-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. In the cases with induced abortion, hCG was detectable from 16 to 60 days, with a median of 30 days after uterine evacuation, in those with spontaneous abortion from nine to 35 days with a median of 19 days, and in the cases of ectopic pregnancy from one to 31 days with a median of eight, five days after laparotomy and removal of the affected tube. There was a significant correlation between the initial hCG levels and the disappearance time in each series. The demonstrated disappearance times are longer than previously recognized, which should be appreciated when hCG is analyzed after termination of early pregnancy.