A Comparative Study on Different Combinations of Cryoprotectants in Vitrification of Mammalian Oocyte: A Review

Oocyte cryopreservation is now widely used in Assisted Reproductive Technology (ART). Vitrification of oocyte is now considered to be an efficacious method for eligible patients who want to preserve their fertility for medical and nonmedical indications. However, oocyte vitrification has been facing its own challenges due to the unique structure of oocyte. A successful vitrification program relies on the proper type and combination of cryoprotectants. This review summarizes the results of several existing literature on mammalian oocyte vitrification and post-thaw oocyte development with the main focus on different combinations of cryoprotectants. We aim to compare the effectiveness of various cryoprotectants and to introduce optimal combination of multiple cryoprotectants in vitrification media of mammalian oocyte. Lastly, main properties of permeable and impermeable cryoprotective agents are briefly discussed by highlighting their advantages and disadvantages.