Theoretical and experimental basis of oocyte vitrification

In the last decades significant advances have been made in successful cryopreservation of mammalian oocytes. Human oocyte cryopreservation has practical application in preserving fertility for individuals at risk of compromised egg quality due to cancer treatments or advanced maternal age. While oocyte cryopreservation success has increased over time, there is still room for improvement. Oocytes are susceptible to cryodamage; which collectively entails cellular damage caused by mechanical, chemical or thermal forces during the vitrification and warming process. This review will delineate many of the oocyte intracellular and extracellular structures that are/may be stressed and/or compromised during cryopreservation. This will be followed by a discussion of the theoretical basis of oocyte vitrification and warming, and a non-exhaustive review of current experimental data and clinical expectations of oocyte vitrification will be presented. Finally, a forward-thinking vision of a potential means of modifying and improving vitrification and warming procedures and success will be proposed. (C) 2011, Reproductive Healthcare Ltd. Published by Elsevier Ltd. All rights reserved.