From a backup technology to a strategy-outlining approach: the success story of cryopreservation

Cryopreservation of oocytes and embryos is a fashionable subject of reviews. This is not only the subjective impression of the authors, it can be justified by a simple PubMed search for 'cryopreservation' or 'vitrification' or 'freezing', and 'oocyte' or 'embryo', with the additional filters for '10 years', 'humans' and 'review', resulting in 360 hits, with 87 of them focusing primarily on cryopreservation (based on individual evaluation of abstracts performed by authors). The corresponding numbers of randomized controlled trials during this period were only 69 and 27,respectively. Accordingly, the publication of another review does not improve the 'too much talk, too few work' situation, and can only be justified by sound reasons.