The study looked at how different freezing and thawing methods affect the survival and development of embryos. They used a fast freezing technique called vitrification on fertilized eggs, 4-cell embryos, and morula. The best results were seen with 4-cell embryos, which had high survival rates and good development after thawing. Fast thawing worked better than slow thawing for all stages of embryos. These findings could be helpful for improving the freezing and thawing process for human embryos used in IVF treatments.