GONADOTROPIN-RELEASING-HORMONE AGONIST COMPARED WITH HUMAN CHORIONIC-GONADOTROPIN FOR OVULATION INDUCTION AFTER CLOMIPHENE CITRATE TREATMENT

The objective of this study was to compare hormonal response, luteal p hase adequacy and pregnancy and abortion rates in patients randomized to receive human chorionic gonadotrophin (HCG) or gonadotrophin-releas ing hormone agonist (GnRHa) during ovulation cycles stimulated by clom iphene citrate. Anovulatory patients received either one s.c. dose of tryptorelin (0.1 mg; n = 104) or one i.m. dose of HCG (10 000 IU; n = 106) after clomiphene citrate stimulation had induced enlarged ovarian follicles (>17 mm in diameter). A short-lived, transitory increase in serum luteinizing hormone (98 +/- 9 IU/l) and follicle-stimulating ho rmone (30 +/- 5 IU/l) concentrations was measured at 12 h following th e injection of GnRHa, and these concentrations returned to baseline le vels by 36 h post-injection. Midluteal progesterone concentrations wer e similar in both groups (>10 ng/ml), and the mean luteal phase durati on was also not significantly different (13 days). There were no signi ficant differences in the mean number of pregnancies (12.0 versus 12.6 % per cycle) and the abortion rate (18.2 versus 12.5%) between the GnR Ha- and HCG-treated groups respectively. There were no complications r elated to treatment in either group. The results show that a relativel y low dose of GnRHa can be used in place of HCG to induce ovulation in clomiphene citrate-treated patients.