Importance of Cumulus Cells in Oocyte Maturation and Conservation Strategies to Improve Vitrification Results

Abstract

Vitrification is not a recent technique, it was firstly described in 1934, but was not successful until years later because the effects of the cryoprotectants (CPAs) used were unknown. Later, in 1985, Rall and Fahy [1] resumed the application of ultrafast cryopreservation by reducing the toxicity of the media and decreasing exposure times, modifying temperatures in order to improve their results [2]. In this way, the cryopreservation basis has been broadened with the aim of optimising conditions for the development of this process. Some of the main concerns are, the formation of intracellular and extracellular ice crystals, the CPAs toxicity and the osmotic changes during vitrification [3].