Clinical outcome following stimulation with highly purified hMG or recombinant FSH in patients undergoing IVF: a randomized assessor-blind controlled trial

BACKGROUND: LH activity may influence treatment response and outcome in IVF cycles. METHODS: A randomized, assessor-blind, multinational trial compared ongoing pregnancy rates (primary end-point) in 731 women undergoing IVF after stimulation with highly purified menotrophin (HP-hMG) (n = 363) or recombinant FSH (rFSH) (n = 368) following a long GnRH agonist protocol. Patients received identical pre- and post-randomization interventions. One or two embryos were transferred on day 3. RESULTS: More oocytes were retrieved (P < 0.001) after rFSH treatment (11.8) compared with HP-hMG treatment (10.0), but a higher proportion developed into top-quality embryos (P = 0.044) with HP-hMG (11.3%) than with rFSH (9.0%). At the end of stimulation, lower estradiol (E-2) (P = 0.031) and higher progesterone (P < 0.001) levels were found with rFSH, even after adjusting for follicular response. The distribution of hypo-, iso- and hyper-echogenic endometrium showed a significant (P = 0.023) shift towards the hyperechogenic pattern after rFSH treatment. The ongoing pregnancy rate per cycle was 27% with HP-hMG and 22% with rFSH [odds ratio (95% confidence interval): 1.25 (0.89-1.75)]. CONCLUSION: Superiority of HP-hMG over rFSH in ongoing pregnancy rate could not be concluded from this study, but non-inferiority was established. Pharmacodynamic differences in follicular development, oocyte/embryo quality, endocrine response and endometrial echogenicity exist between HP-hMG and rFSH preparations, which may be relevant for treatment outcome.