Timing of The First Zygotic Cleavage Affects Post-Vitrification Viability of Murine Embryos Produced In Vivo.

Background: Timing of the first zygotic cleavage is an accurate predictor of embryo quality. Embryos that cleaved early (EC) have been shown to exhibit higher develop- mental viability compared to those that cleaved at a later period (LC). However, the vi- ability of EC embryos in comparison to LC embryos after vitrification is unknown.