Background: This study compares the influence of recombinant (r)FSH and urinary (u)FSH stimulation on oocyte and embryo quality in patients undergoing ICSI.
Methods and results: Denuded oocyte maturity in ICSI patients was graded on a scale from metaphase II (MII) to prophase for nuclear maturation of oocytes. The relationships of cumulus-free oocyte maturational profiles with in vitro outcome parameters were evaluated. In the study population with an unknown distribution of FSH receptor polymorphisms, the ovarian response to rFSH stimulation was significantly different from that of uFSH stimulation, including lower number of oocytes retrieved/oocytes in MII, higher fertilization rates and higher good quality embryo rates. In the study population with a similar distribution of FSH receptor polymorphisms, the ovarian responses to rFSH were lower numbers of oocytes in MII, higher fertilization rates and higher good quality embryo rates, but the total number of oocytes retrieved was not influenced, in comparison with ovarian stimulation with uFSH.
Conclusions: rFSH stimulation appears to influence oocyte quality and subsequent embryo quality in comparison with uFSH stimulation. FSH receptor polymorphisms seem to be an intrinsic factor influencing the ovarian response to FSH stimulation.