Objective: The purpose of this study was to determine the normal beta-human chorionic gonadotropin change within 24 hours after a medical abortion. Because a medical abortion creates a "miscarriage," these data can represent the serum beta-human chorionic gonadotropin changes that would occur with a complete spontaneous abortion. Knowledge of normal beta-human chorionic gonadotropin changes after a spontaneous abortion may help to differentiate within a 24-hour period a complete from an incomplete spontaneous abortion or an ectopic pregnancy.
Study design: Data from recent trials that used methotrexate and misoprostol for abortion at < or = 56 day's gestation were reviewed. Patients from each of four trials were included in this analysis if (1) they received both methotrexate intramuscularly and misoprostol vaginally and (2) they had serum beta-human chorionic gonadotropin levels drawn on both the day of misoprostol administration and the next day.
Results: The change in serum beta-human chorionic gonadotropin was evaluated in 86 patients. Subjects who had a complete abortion after receiving methotrexate and a single dose of misoprostol had a decline in serum beta- human chorionic gonadotropin of 66% +/- 8%. All other subjects had a decline of 25% +/- 19% (p=0.0001).
Conclusions: An aborting pregnancy, if the abortion has occurred, should have a beta-human chorionic gonadotropin decrease of at least 48% within approximately 24 hours. This decline, however, does not guarantee that the abortion is complete. A patient with a serum beta-human chorionic gonadotropin level that has not declined by a minimum of approximately 50% over 24 hours is unlikely to have a complete abortion.
PIP: The purpose of the study was to determine the normal beta-human chorionic gonadotropin change within 24 hours after a medical abortion to differentiate a complete from an incomplete spontaneous abortion or an ectopic pregnancy. 171 English- and Spanish-speaking pregnant women were recruited for four prospective trials by the University of California, San Francisco. Three trials included women under 56 days' gestation and a fourth trial included women between 57 and 63 days' gestation. Patients from the 1st trial group received methotrexate 50 mg/sq. meter im, followed 3 days later by misoprostol 800 mcg vaginally. In the 2nd trial group, patients were randomized to receive methotrexate 50 mg/sq. meter im, followed by misoprostol or misoprostol alone. In the 3rd trial group, patients were randomized to receive methotrexate 50 mg/sq. meter im, followed by misoprostol 3 days later (group 1) or 7 days later (group 2). In the 4th trial group patients between 57 and 63 days' gestation received methotrexate 50 mg/square meter im followed 3 days later by misoprostol 800 mcg vaginally. 86 women met the criteria for evaluation of the change in serum beta-hCG levels on the day after misoprostol administration. 3 of these patients had incomplete abortion (1 immediate success and 2 delayed successes). The change in beta-hCG on the day after the initial misoprostol administration for these was -67%, -20%, and -19%, respectively. 48 women received the first dose of misoprostol 3 days after methotrexate and 38 women received misoprostol 7 days later. Subjects who had complete abortion after receiving methotrexate and a single dose of misoprostol had a decline in serum beta-hCG of 66% +or- 8%. All other subjects had a decline of 25% +or- 19% (p = .0001). An aborting pregnancy, if the abortion has occurred, should have a beta-hCG decrease of approximately 50% within about 24 hours. However, a patient with a serum beta-hCG level that has not declined approximately 50% over 24 hours is unlikely to have a complete abortion.