ABSTRACT
INTRODUCTION Decades ago, most assisted reproductive technologies including in vitro fertilization (IVF) and cryopreservation of embryos by traditional freezing were applied to humans almost immediately aer the rst successes in some experimental or domestic species. However, there are some techniques where eorts to adopt a new approach were insucient and sporadic, and consequently the practical application has been considerably delayed. Vitrication belongs to the latter group. Reasons for this delay may include the fact that cryopreservation of zygote-, cleavage-, and blastocyst-stage human embryos was more or less resolved by traditional freezing; vitrication has and still uses a seemingly very “undeveloped” manual technology compared to automatic traditional freezers and standardized, ready-to-use media. e high concentrations of cryoprotectants required for vitrication discouraged some potential users initially. Finally, none of the major suppliers were eager to replace their expensive freezing machines with the much simpler system required for vitri-cation (though very recently there have been some eorts to develop an instrument that would allow a “semi-automated” vitrication process [1]).
