Compared to fresh egg insemination, intracytoplasmic sperm injection after thawing of frozen eggs results in lower embryo conception rate, lower embryo quality and lower blastocyst formation rate. However, the pregnancy rate of fresh embryo implantation is the lowest

 

Fresh Egg Insemination to form Embryo Cryo-Thaw Implantation Pregnancy Rate > Egg Cryo-Thaw Fertilization to form Embryo Re-implantation Pregnancy Rate > Fresh Egg Embryo

 

Frozen eggs were inferior to fresh eggs in terms of fertilization rate (80% vs 85%), quality embryos on the third day of culture (31% vs 39%), and blastocyst development on the fifth day (36% vs 41%).

 

Freeze-all, oocyte vitrification, or fresh embryo transfer? Lessons from an egg-sharing donation program 

 

Fertil Steril 2016;106:615-22. 2016

 

◉ Decreased embryo quality and lower rates of blastocyst formation were observed among embryos derived from vitrified oocytes. 

◉ The highest pregnancy and implantation rates were noted for the Thaw Cycles Group, followed by the Banked Donor Egg Group. 

◉ the Fresh Cycles Group had the lowest rates. 

◉ Conclusion(s): Oocyte vitrification followed by intracytoplasmic sperm injection leads to lower embryo developmental competence compared with when fresh insemination methods are used. 

◉ However, pregnancy and implantation rates are higher when embryos are transferred into a ''more receptive'' endometrium, free of the adverse effects of gonadotropin. ' endometrium, free of the adverse effects of gonadotropin.