Lack of reproducibility in oocyte vitrification calls for a simpler (whether semi-manual or automatic) and standardized methodology

The article of Tannus et al. 2018 [1] in this issue of the journal brings to the forefront an important issue in oocyte vitrification: the lack of reproducible results. The case reported is important because it shows that even in the same IVF lab and with the same methodology carried out by embryologists (senior or young) of the same team, the results differ dramatically. Time has arrived to standardize the methodology since, as noted by previous colleagues [2], there are too many protocols for vitrification and even subtle changes may ultimately have a profound impact on the outcome. Vitrification differs from the slow-freezing technology and it is helpful to clarify the differences and the terminology.