Developmental competence and apoptotic gene expression patterns of mature and immature human oocytes retrieved from controlled ovarian stimulation cycles

Abstract

The purpose was to assess the developmental competence of the in vitro or in vivo matured human oocytes as well as the apoptotic genes expression of cumulus cells (CCs) regarding nuclear maturity status of associated oocytes retrieved from stimulated ICSI cycles. A total of 590 oocytes and the associated CCs were retrieved and divided into groups of test and control according to the nuclear maturity status in order to the developmental evaluation as well as expression patterns of apoptosis-related genes using real time PCR. The fertilization and embryo formation rates were 60.3% and 87.5% vs.69.1% and 92.8% in test and control groups, respectively. Good quality embryos on day 3 were 62.2% in test and 69.1% in control groups. There were significant differences in the rates of normal fertilized as well as unfertilized oocytes between the groups. Also, mRNA levels of some apoptotic genes were significantly higher in the CCs obtained from immature oocytes among patients with premature ovarian factors (POF) rather than other infertility etiologies (p < 0.001). The data demonstrated the developmental competence of in vitro matured oocytes -even to good quality cleavage embryos- is not completely consistent with molecular integrity and well-mannered gene expression patterns resulting to ICSI success. It seems that using immature oocytes could be helpful for patients at risk of ovarian hyperstimulation syndrome (OHSS) as the same as patients with diminished ovarian reserve.

Keywords: Apoptosis; Cumulus cell; Gene expression; Human oocyte; In vitro maturation.