Similar ovulation rates, but different follicular development with highly purified menotrophin compared with recombinant FSH in WHO Group II anovulatory infertility: a randomized controlled study

BACKGROUND: The contribution of the LH activity in menotrophin preparations for ovulation induction has been investigated in small trials conducted versus FSH preparations. The objective of this study was to demonstrate non-inferiority of highly purified urinary menotrophin (HP-HMG) versus recombinant FSH (rFSH) with respect to the primary outcome measure, ovulation rate. METHODS: This was a randomized, open-label, assessor-blind, multinational study. Women with anovulatory infertility WHO Group II and resistant to clomiphene citrate were randomized (computer-generated list) to stimulation with HP-HMG (n=91) or rFSH (n=93) using a low-dose step-up protocol. RESULTS: The ovulation rate was 85.7% with HP-HMG and 85.5% with rFSH (per-protocol population), and non-inferiority was demonstrated. Significantly fewer intermediate-sized follicles were observed in the HP-HMG group (P<0.05). The singleton live birth rate was comparable between the two groups. The frequency of ovarian hyperstimulation syndrome and/or cancellation due to excessive response was 2.2% with HP-HMG and 9.8% with rFSH (P=0.058). CONCLUSIONS: Stimulation with HP-HMG is associated with ovulation rates at least as good as a rFSH in anovulatory WHO Group II women. LH activity modifies follicular development so that fewer intermediate-sized follicles develop. This could have a positive impact on the safety of ovulation induction protocols.