P-145: Maturation Capacity and Viability Assessment of Human Immature Oocytes After Vitrification and In Vitro Maturation (IVM)

Background: 15% of oocytes collected in ART cycles are immature. These oocytes may be matured following IVM program. It is possible to cryopreserve the immature oocytes for further use in ART after application of IVM. The aim was to determine the maturation rate, morphology and viability of human immature oocytes after fresh IVM and vitrified-IVM program. Materials and Methods: 63 women who underwent controlled ovarian stimulation for ART were included. 103 immature oocytes were retrieved from these infertile women aged between 18-43 years old. 53 immature oocytes were used for fresh group and 50 immature oocytes for vitrification group. The maturation medium was Ham’s F10 supplemented with 0.75 IU FSH, 0.75 IU LH and 40% human follicular fluid (HFF). After 48h, maturation and morphology were assessed in fresh-IVM and vitrified-IVM oocytes. Also, viability was assessed using PI/Hoechst staining. Results: Oocytes Maturation rate were reduced in vitrification group (56.0%), in comparison with fresh group (88.7%, p<0.001). Oocyte viability rate after staining were reduced in vitrification group (56.0%), in comparison with fresh group (86.8%, p<0.007). Conclusion: Vitrification reduces both the maturation capacity and viability of human immature oocytes. It is recommended to apply IVM on fresh immature oocytes, instead.