Randomized trial of three luteinizing hormone-releasing hormone analogues used for ovarian stimulation in an in vitro fertilization program.

Objective: To determine if biochemical differences in luteinizing hormone-releasing hormone analogues (LH-RH-a) have a clinical influence, we studied three of these molecules: buserelin acetate (group B), triptorelin (group T), and leuprorelin (group L).

Design: Clinical trial.

Setting: In Vitro Fertilization (IVF) Center.

Patients: Two hundred forty-six patients, undergoing their first IVF attempt, were randomly allocated to one group. The analogues were used in a long protocol for ovarian stimulation in an IVF program.

Results: After 15 days of LH-RH-a therapy, the follicle-stimulating hormone level was lower in group B (2.9 +/- 1, 4.3 +/- 1.7, 4.8 +/- 2.1 UI/L for B, T, and L groups, respectively; P less than 0.001), although no difference was found in LH and estradiol (E2) levels. After follicular growth stimulation by human menopausal gonadotropins (hMG), E2 level was significantly lower in B group (1,799 +/- 1,101, 2,440 +/- 1,298, 2,137 +/- 1,044 pg/mL for B, T, and L groups, respectively; P less than 0.01), as well as the E2 level per hMG ampule (67 +/- 51, 97 +/- 61, 82 +/- 49 for B, T, and L groups respectively; P less than 0.01). The pregnancy per stimulated cycle rate was not significantly different among the groups.

Conclusions: These results suggest that LH-RH-a could act not only on the pituitary but also on the ovaries. Moreover, these data suggest that buserelin acetate could be preferentially used for high responders and triptorelin for poor responders.