The future of human ovarian cryopreservation and transplantation: fertility and beyond

Objective: To review the current progress in ovarian cryopreservation and transplantation and to discuss the obstacles with the clinical application of this technique. Design: The literature on ovarian cryopreservation and transplantation was reviewed to facilitate understanding and predict future directions. The studies related to this topic were identified through MEDLINE and other bibliographic databases, focusing on the most recent developments. Conclusion(s): The experimental evidence for low-temperature storage of ovarian tissue is encouraging. Although restoration of fertility with cryopreserved ovarian grafts has been successful in various animals, there are uncertainties about the optimum use of stored ovarian tissue in humans. Autotransplantation appears to be promising, but the potential risk of transmitting malignant cells in women with cancer is of great concern. The maturation of primordial follicles with xenotransplantation is encouraging, but the efficacy and the safety of this method need further investigation. Furthermore, the quality of oocytes that have been matured in a host animal is unknown. The development of in vitro culture systems for oocyte maturation is still in its infancy. There are many issues to be resolved in ovarian transplantation before the full clinical use of this emerging technique. Most of all, there is an urgent need to optimize the freeze/thaw procedure and to find the means to protect grafts from ischemia-reperfusion injury. Nevertheless, ovarian transplantation should prove to be clinically useful for women at risk for premature ovarian failure.