Disappearance of human chorionic gonadotropin and resumption of ovulation following abortion

Abstract

The disappearance of human chorionic gonadotropin (hCG) and resumption of pituitary ovarian function was investigated in 13 patients following first- and second-trimester abortions. First-trimester abortion patients (with suction curettage) had a mean time of 37.5 +/- 6.4 days for the clearance of hCG to a level of 2 mlU/ml. Second trimester abortions (with prostaglandin) had a mean time of 27.4 +/- 4.8 days. Patients undergoing second-trimester hysterectomy had a mean disappearance time of 39.7 +/- 5.3 days and only 12 days if the hysterectomy was initiated with ligation of the uterine and ovarian vessels. No significant difference in clearance time was found when it was compared on the basis of the baseline hCG levels. Based on a concomitant luteinizing hormone (LH) and follicle-stimulating hormone (FSH) peak, nine of 12 patients resumed normal pituitary function. These LH and FSH peaks were seen even though the serum hCG levels were as high as 35 mlU/ml. Based on serum progesterone levels of greater than 3 ng/ml, all these nine patients ovulated as early as 21 days after abortion. In view of these results, the clearance of hCG after pregnancy termination depends mainly upon the type of procedure used. Moreover, in view of the early time of ovulatory recovery, contraception should be instituted within the first 2 weeks following pregnancy termination.

PIP: The disappearance of human chorionic gonadotropin (hCG) and resumption of pituitary ovearian function was investigated in 13 patients following 1st- and 2nd-trimester abortions. The patients were selected on the basis of previous good health and an uneventful pregnancy. Baseline blood samples were obtained within 24 hours of the initiation of the abortion. Daily blood samples were then obtained for 507 days in all patients. Subsequently, serum samples were obtained twice weekly for 42-55 days after abortion. The serum was separated by centrifugation and stored at -20 degrees C until assays were performed. Serum levels of luteinizing hormone (LH), follicle-stimulating hormone (FSH), the beta subunit of hCG, and progesterone were measured by radioammunoassay procedures. 1st trimester abortion patients (with suction curettage) had a mean time of 37.5 + or - 6.4 days for the clearance of hCG to a level of 2mlU/ml. 2nd trimester abortions (with prostaglandin) had a mean time of 27.4 + or - 5.3 days and only 12 days if the hysterectomy was initiated with ligation of the uterine and ovarian vessels. No significant difference in clearance time was found when comparison was on the basis of the baseline hCG levels. Based on a concomitant LH and FSH peak, 9 of 23 patients resumed normal pituitary function. These LH and FSH peaks were observed even though the serum hCG levels were as high as 35 mlU/ml. Based on serum progesterone levels of greater than 3 ng/ml, all 9 patients ovulated as early as 21 days following the abortion. In terms of these results, the clearance of hCG after abortion is dependent primarily on the type of procedure used.