17 - Vitrification of human oocytes using the McGill Cryoleaf protocol

Summary

Oocyte cryopreservation represents an attractive and the least invasive option of fertility preservation strategy for patients wishing to retain their choice of a male partner. Recent advances in vitrification techniques have markedly improved the efficacy of oocyte cryopreservation, demonstrating that vitrification may be more effective than the conventional slow-cooling method. The proposed mechanism of vitrification uses a high concentration of cryoprotectant (CPA) and extremely rapid cooling and warming rates in order to avoid intra-and extracellular ice formation. The commonly used CPAs for cryopreservation of oocytes and embryos are small neutral solutes such as ethylene glycol (EG), 1,2-propanediol (PROH), dimethyl sulfoxide (DMSO), and glycerol. Some devices used for vitrification include the McGill cryoleaf, cryotip, cryotop, nylon loop or cryoloop, thin capillary or open pulled straws, hemi-straws, and electron microscope copper/gold grids. The oocyte vitrification technique offers a realistic hope of fertility preservation for women without partners.