Recombinant human luteinizing hormone to trigger ovulation: randomized, controlled, dose-finding pilot study in ovulation induction.

Objective: To evaluate recombinant human luteinizing hormone (r-hLH) versus urine-derived human chorionic gonadotropin (u-hCG) to trigger ovulation in women (aged 20-40 years) with WHO Group II anovulatory infertility undergoing ovulation induction (OI) with recombinant human follicle-stimulating hormone (r-hFSH) (150 IU/day starting dose).

Study Design: For this Phase II, open-label, dose-finding pilot study, patients were randomized to doses of 825, 2,750, 5,500, 11,000, or 22,000 IU r-hLH or u-hCG (5,000 IU). Primary endpoints were ovulation and ratio of ruptured follicles/follicle > or = 15 mm (day of r-hLH/ u-hCG administration). Secondary endpoints included monofollicular ovulation and clinical pregnancy rates.

Results: All 67 randomized patients completed treatment. All patients in the r-hLH 2,750 (13/13), 5,500 (12/ 12), 11,000 IU (13/13), and u-hCG 5,000 IU (12/ 12) groups ovulated; 3/5 patients in the r-hLH 825 IU and 2/12 in the r-hLH 22,000 IU group failed to ovulate (p = 0.105 between evaluable groups). The mean ratio of ruptured follicles/ follicle > or = 15 mm was 1.1 (p = 0.675 between groups). The monofollicular ovulation rate was 15/60 (25%). Two cases of ovarian hyperstimulation syndrome were reported.

Conclusion: This open-label, pilot study (conducted in 1999-2001) suggests that the minimal effective dose of r-hLH to trigger ovulation in women with WHO Group II anovulatory infertility undergoing OI with r-hFSH (150 IU starting dose) was 2,750 IU.