Supplementation of IVM culture media with GDF-9 can potentially enhance oocyte quality, fertilization and embryo development in ICSI procedure

Abstract

In vitro maturation (IVM) of human oocytes is important in assisted reproductive technology (ART) laboratories. The present study aimed to investigate the effect of growth differentiation factor 9 (GDF-9) additions into IVM medium, and co-culture of cumulus cells (CCs) on IVM outcome. 385 immature oocytes in germinal vesicle (GV) stage were divided into four groups based on the IVM culture condition; 1) GV oocytes cultured in standard IVM medium (control), 2) GV oocytes co- cultured with CCs, 3) GV oocytes treated with GDF-9, and 4) GV oocytes co- cultured with CCs and treated with GDF-9, simultaneously. The presence of meiotic spindle (MS) and zona pellucida (ZP) birefringence were assessed in IVM oocytes, followed by intracytoplasmic sperm injection (ICSI). Finally, fertilization rate and embryo development in two-day-old embryos were evaluated. Maturation rates of GV oocytes were similar a whole groups following 24-48 h of incubation. A significant higher rate of oocytes matured in the medium treated with CCs reached 2 pronuclear (2PN) stage compared with those matured in the standard medium, respectively (76.5% vs. 51.6%, P= 0.01). The percentage of oocytes with visible MS was higher in all treated groups, but this difference was significant between the oocytes matured in medium supplemented with GDF-9 and control group (45% vs. 26.6% respectively, P= 0.05). Co-culturing of GV oocytes with CCs and/or supplementation of IVM medium with GDF-9 are potentially involved in improvement of fertilization and embryo development. Also, MS assessment provides an early predictor of embryo development.