Pregnancy-Specific Beta-1-Glycoprotein and Chorionic Gonadotropin Levels After First-Trimester Abortions

Abstract

The scrum levels of pregnancy-specific beta-1-glycoprotein (PSBG) and human chorionic gonadotropin (hCG) were measured by specific radioimmunoassays in 102 women undergoing legal early first-trimester abortions induced by 15-methyl-prostaglandin F2« (PG) vaginal suppositories. In all cases PSBG and hCG were readily detectable 3-5 weeks after conception. After PG administration 9 patients failed to abort and high PSBG and hCG levels were maintained. Ninety-three patients aborted. Six hours after PG administration PSBG and hCG were present at high concentrations in all cases, and after 1 week both markers were found in 66 aborted cases (71%). Human chorionic gonadotropin alone was present in 22 cases (24%), and PSBG alone in one case. Both markers had leveled off in 3 patients (3.2%). After 2 weeks PSBG and hCG were found in 49 women (53%). hCG alone in 20 (22%), PSBG alone in 2 cases, and neither in 22 cases (24%). When 4 weeks had passed PSBG and hCG were still present in 16 women (17%), hCG alone in 9 (9.7%), and PSBG alone in 8 (8.6%). In clinically uncomplicated abortions, PSBG and hCG disappeared from serum more rapidly than in those women in whom bleeding was prolonged. Thus, after PG abortion hCG secretion is usually maintained longer than that of PSBG, hut the opposite may also happen. In women with uncomplicated abortions no difference was noted in the onset of postabortion menses between women who presented with trophoblastic markers and those who did not. As a product of the placental trophoblast, PSBG is likely to be a valuable adjunct to hCG in the detection of trophoblastic activity.