A Series of Monozygotic Twins Discordant for Ovarian Failure: Ovary Transplantation (cortical Versus Microvascular) and Cryopreservation

Background: A series of monozygotic (MZ) twin pairs discordant for premature ovarian failure presented an unusual opportunity to study ovarian transplantation.

Methods: Ten MZ twin pairs requested ovarian transplantation and eight have undergone transplantation with cryopreservation of spare tissue. Seven had a fresh cortical tissue transplant, one of whom received a second frozen-thawed transplant after the first ceased functioning at three years. One had a fresh microvascular transplant.

Results: All recipients reinitiated ovulatory menstrual cycles and normal Day 3 serum FSH levels by 77-142 days. Six have already conceived naturally (one twice). Currently, two healthy babies have been delivered, and another three pregnancies are ongoing. The oldest transplant functioned for 36 months, resulting in one child and one miscarriage. She conceived again after a frozen-thawed secondary transplant. There was no apparent difference in return of ovarian function between the eight fresh ovarian grafts and the one frozen graft.

Conclusions: Ovarian transplantation appears to restore ovulatory function robustly. Successful pregnancies, including one after cryopreservation, bode well for application to fertility preservation.