Evaluation of VitriBlast™ for vitrification of immature oocytes

Abstract: Cryopreservation of gametes and embryos is crucial in fertility treatment and fertility preservation. Preservation of oocytes is a more complicated process than preservation of sperm and embryos. According to recent studies, a new preservation technique called vitrification is found to have higher rates of oocytes-survival after warming    The aim of this study was to evaluate VitriBlast™ Kit, for vitrification of oocytes. Vitrification is an ultra-rapid freezing method in the presence with of high concentrations of cryoprotectants which avoids intracellular ice-crystal formation during the freezing and warming process.     In this study, a total number of 117 immature oocytes were used and 62 of these oocytes were vitrified with VitroBlast™ Kit. During this process two different vitrification devices were used, VitroLoop™ and Cryopette®. After warming, the average survival rate for vitrified oocytes was found to be 61% for VitroLoop™ and 15% for Cryopette® (p<0.001). The remaining 55 oocytes were used as a non-frozen control group and the same incubation method as for vitrified oocytes was used. The survival rate for the control groups was higher than for the vitrified groups (93% versus 35%, p<0.001). The results of this study indicate that VitriBlast™ Kit is not suitable for vitrification of oocytes.