O-96:Differences In Endocrine AndParacrine Milieu Induced By HPhMG(MENOPUR) Compared TorFSH (GONAL-F) Influencing LifeBirth Rate

It has been demonstrated in several models that the LH activity brings a dimension of quality in the cohort of follicles recruited by FSH. Evidence is accumulating that a supplementation of LH-activity independent of endogenous LH levels might be beneficial for pregnancy outcome. Recent data suggest differences in efficacy of treating women with follicle-stimulating hormone (FSH) alone and gonadotrophins containing LH-activity. LH plays a dual role in folliculogenesis. It promotes follicular development and maturation through the production of androgen and growth factors in theca and granulosa cells. Additionally, LH appears to be involved in the negative selection of smaller follicles within the first few days of the stimulation–probably via a shift in the androgen/estrogen balance. Unlike recombinant follicle-stimulating hormone (rFSH), highly purified human menopausal gonadotrophin (MENOPUR) contains both FSH and human chorionic gonadotrophin (hCG), a source of long-acting LH-activity. Abstract of the 8th Royan International Twin Congress, Tehran, Iran, 5-7 September 2007 Yakhteh Medical Journal, Vol 9, Sup 1, Summer 2007 57 The Menotrophin versus Recombinant FSH in in vitro fertilisation Trial (MERiT®) showed a trend towards a reduced number of oocytes at retrieval, which nonetheless, developed into a significantly higher number of top quality embryos per oocyte retrieved with MENOPUR versus rFSH. The hCG-driven LH-activity in MENOPUR happens to be the key differentiator driving the selection towards better quality follicles for in vitro fertilisation cycles. The different gonadotrophins lead to an endocrine profile with a major impact on the endometrium. MERiT found that progesterone levels were significantly lower on the days of hCG and oocyte retrieval with MENOPUR compared with rFSH and these lower progesterone levels were associated with higher implantation and ongoing pregnancy rates. Further analysis of cumulus-corona cells in patients treated with MENOPUR or GONAL-F showed a significant difference in gene expression on the day of oocyte retrieval in approximately 500 genes. Some of the genes changed by Menopur are known quality genes expressed in cumulus after stimulation. This data (unpublished from the authors' laboratory) might lead to a better understanding of cumulus-corona cell function in relation to oocyte quality and is an interesting subject of research. Together, these data suggest that the hCGdriven LH-activity present in MENOPUR brings a significant change in the close environment of the oocyte and in the hormonal balance that might influence endometrial receptivity, compared with rFSH.