Fast to fastest: single-step sucrose dilution to direct hydration of vitrified-warmed human blastocysts

With the publication of several recent papers on new vitrification and post-warming protocols, Reproductive BioMedicine Online has brought well-deserved attention to the evolving landscape of cryopreservation practices for human oocytes and embryos. These new protocols aim to improve efficiency, reliability, cost-effectiveness and, potentially, safety and the developmental trajectory. Vitrification protocols have changed from long to short (as in 'fast and furious') and post-warming dilutions have changed from a multistep process to a fast single-step process. However, we may yet see warming protocols that forgo elution in non-permeable solutes in favour of an even faster method - rehydration directly in culture medium.