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

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. Moreover, the freeze-all method leads to exceptional clinical outcomes.