Morphokinetics analysis of embryos derived from vitrified/warmed oocytes

Abstract

Purpose Oocyte vitrification is a worldwide used technique that has proved its worth. Although it was shown not to alter oocyte integrity, a recent study concluded that it may affect oocyte embryo development. As the morphology and kinetics of embryos derived from sibling fresh and vitrified oocytes have not been described previously, the present study evaluates cleavage rate, blastomeres size, fragmentation rate, and blastocyst formation in vitrified/warmed oocyte derived embryos (VODE) as compared with sibling fresh oocytes derived embryos (FODE). Methods This investigation included 90 infertility cases displaying large cohort of mature oocytes at pick up, divided into 2 groups after denudation. A part of oocytes underwent ICSI while others were vitrified. Oocyte warming cycles were performed when no pregnancy was achieved using fresh eggs. Zygote to blastocyst development was recorded prospectively in an image database up to day 5. Results VODE did not show major difference as compared with FODE in terms of cleavage rate, number of blastomeres, fragmentation rate, and blastomeres size. Furthermore, percentage of morulae at day 4 and blastocysts at day 5 are not affected by oocyte vitrification. Conclusion Although our results show that embryo development is not altered by oocyte vitrification, offspring follow-up is essential to exclude any adverse developmental effect of the technique.

Oocyte vitrification does not affect early developmental timings after intracytoplasmic sperm injection for women younger than 30 years old

“…Considering the timing of early divisions—particularly the second, third, and fifth cleavages—is the best indicator of embryo viability and the ability to reach blastocyst stage (Meseguer et al, , ; Basile et al, ), we do not believe that vitirification negatively impacts preimplantation development. Indeed, oocyte vitrification did not affect the morphokinetic development of embryos (Montjean et al, ).…”

Is it worth it to cryopreserve embryos with blastulation delay at day 5?

“…Embryos obtained after IVF, ICSI and ICSI-VWO were cultured under the same conditions; in global medium (LifeGlobal®, France) microdrops covered with mineral oil under standard culture conditions (37°C, CO 2 6%). As previously described, morphology was assessed using the simplified Gardner grading system (from B1 to B6), and recorded prospectively in an image database (Pegase software, 2iSYSTEM, France) before vitrification and after warming (Boyer and Boyer, 2009;Montjean et al, 2015). Embryos were classified in three grades embryo categories based on their expansion degree as described above (Fig.…”