Influence of ovarian stimulation with HP-hMG or recombinant FSH on embryo quality parameters in patients undergoing IVF.

BACKGROUND

There are limited data on the impact of different gonadotrophin preparations on embryo quality.

METHODS

This evaluation was part of a randomized, assessor-blind, multinational trial, conducted in 731 women undergoing IVF after stimulation with highly purified human menopausal gonadotropin (HP-hMG; MENOPUR) (n = 363) or recombinant FSH (rFSH; GONAL-F) (n = 368). Ongoing pregnancy was the primary end-point [HP-hMG 27% and rFSH 22%; odds ratio (OR) (95% confidence interval, CI) 1.25 (0.89-1.75)]. All 7535 oocytes retrieved were evaluated daily until day 3 (embryo transfer) in a blinded manner both by local site embryologists and a central panel of three embryologists.

RESULTS

The proportion of top-quality embryos per oocyte retrieved was higher with HP-hMG (11.3%) compared with rFSH (9.0%) (P = 0.044) in the local assessment, but comparable in the central assessment (9.5 and 8.0%, respectively). Significant differences in favour of HP-hMG were observed for number of blastomeres and degree of fragmentation, while uniformity of blastomere sizes, localization of fragments, frequency of multinucleation and homogeneous cytoplasm were comparable between HP-hMG and rFSH. The live birth, ongoing pregnancy and ongoing implantation rates for top-quality embryos were higher with HP-hMG than rFSH [48 versus 32% (P = 0.038), 48 versus 32% (P = 0.038), 41 versus 27% (P = 0.032)]. Both the proportion of embryos with at least 50% surviving blastomeres after cryopreservation and embryos resuming mitosis were more frequent with HP-hMG compared with rFSH.

CONCLUSIONS

Composition of gonadotrophin preparations used during ovarian stimulation has an impact on some embryo quality parameters. The capacity to implant of the top-quality embryos derived from stimulation with HP-hMG appears to be improved, although the mechanism needs to be elucidated.