Should All Embryos from Day 1 Rescue Intracytoplasmic Sperm Injection Be Transferred During Frozen-thawed Cycles?

A retrospective analysis of a 5-year rescue intracytoplasmic sperm injection (ICSI) experience performed in 17 cases of complete IVF fertilization failure showed that the ongoing pregnancy rate per embryo transfer (ET) is much higher in a subsequent frozen-thawed cycles (40%, 2/5) than following a fresh ET (6.7%, 1/15). These results suggest that cryopreservation of all embryos, subsequently used in frozen-thawed cycles, might improve rescue ICSI outcome throughout a better synchronization of the embryo development with the endometrium.