Comparison outcome of fresh and vitrified donor oocytes in an egg-sharing donation program

Objective To compare the survival, fertilization, early embryonic development, and clinical outcomes from fresh and vitrified cohort oocytes. Design Review of egg-sharing program, in which the eggs from one donor were shared by recipients of fresh and vitrified eggs. Setting IVF center. Patient(s) 77 women, comprising 36 patients receiving vitrified donor oocytes and 41 patients receiving fresh donor oocytes. Intervention(s) Shared donor eggs vitrified by the Cryotop method warmed after vitrification, with microinjection of surviving metaphase 2 (MII) or fresh oocytes. Main Outcome Measure(s) Survival, fertilization, cleavage rate, pregnancy rate, and implantation. Result(s) Of the vitrified oocytes, 192 (91.4%) survived. There was no statistically significant difference in fertilization and cleavage rates, embryo quality, or clinical results obtained from vitrified compared with fresh oocytes. The outcomes of cycles using fresh oocytes were predictive of the cycle outcomes after warming of oocytes from the same cohort. Conclusion(s) Oocyte donations using vitrified oocytes can provide the same quality of embryos, pregnancy, and implantation potential as fresh oocyte donations.