Vitrification has detrimental effects on maturation, viability, and subcellular quality of oocytes post IVM in cancerous women: An experimental study

Background: In vitro maturation (IVM) of immature oocytes retrieved from ovariantissue has been considered as a valuable approach for fertility preservation incancerous patients.Objective: To evaluate the efficacy of vitrification on oocyte maturation, survival rates,as well as the subcellular oocyte quality post IVM.Materials and Methods: The ovarian cortexes from 19 women with cervix and uterinemalignancy aged 21–39 yr were collected. Cumulus-oocyte complexes were aspiratedfrom all visible antral follicles. 102 immature oocytes were collected, and 43 oocyteswere detected appropriately for IVM (control group). Also, 59 immature oocytes werevitrified, then matured in vitro (IVM) in two groups: with Growth/differentiation factor9 (GDF9) (group 1) and without GDF9 (group 2) supplementation. Rates of oocytesviability, maturation, and survival along with meiotic spindle visualization and zonapellucida birefringence were assessed with Polyscope.Results: The rate of maturation was significantly higher in controls (55.8%) comparedto the other groups. Maturation rate was 23.3% in oocytes cultured in IVM mediumenriched with GDF9, and 27.6% in those cultured in IVM medium lacking GDF9 (p= 0.86). Also, the meiotic spindle was present in 74.4% of control oocytes whichwas significantly higher than the other groups. The proportion of high zona pellucidabirefringence was higher in the controls when compared with group 1 (51.2% vs. 23.3%,respectively, p = 0.04).Conclusion: Vitrification had a detrimental effect on oocyte maturation, viability as wellas the subcellular quality of the oocytes after IVM in cancerous women.

Keywords:

IVM , Vitrification , Fertility preservation , Maturation rate , Meiotic spindle , Zona pellucida birefringence