Human oocyte and ovarian tissue cryopreservation and its application.
OBJECTIVE
To review the recent progress in human oocyte and ovarian tissue cryopreservation, and in the application of these two technologies for preserving female fertility of patients who are undergoing cancer treatment.


METHODS
The literature on human oocyte and ovarian tissue freezing was searched with PubMed. The scientific background, current developments and potential future applications of these two methods were reviewed.


RESULTS
Chemotherapy and/or radiotherapy can induce premature ovarian failure in most of female cancer patients. Consequently, there has been a greater need for options to preserve the reproductive potential of these individuals. However, options are somewhat limited currently, particularly following aggressive chemotherapy and/or radiotherapy treatment protocols. In recent years, there have been considerable advances in the cryopreservation of human oocytes and ovarian tissue. For women facing upcoming cancer therapies, cryopreservation of ovarian tissue and oocytes is a technology that holds promise for banking reproductive potential for the future. Recent laboratory modifications have resulted in improved oocyte survival, oocyte fertilization, and pregnancy rates from frozen-thawed oocytes in IVF. This suggests potential for clinical application.


CONCLUSIONS
In the case of patients who are facing infertility due to cancer therapy, oocyte cryopreservation may be one of the few options available. Ovarian tissue cryopreservation can only be recommended as an experimental protocol in carefully selected patients. In ovarian tissue transplantation, more research is needed in order to enhance the revascularization process with the goal of reducing the follicular loss that takes place after tissue grafting. These technologies are still investigational, although tremendous progress has been made. The availability of such treatment will potentially lead to its demand not only from patients with cancer but also from healthy women who chose to postpone childbearing until later in life and therefore wish to retain their fertility.
Tao
Tao
T
The Toronto Institute For Reproductive Medicine, Toronto, ON, Canada. ttao@repromed.ca
Del Valle
Alfonso
A
D000970:Antineoplastic Agents / Q000009:adverse effects; D015925:Cryopreservation / Q000295:instrumentation / Q000379:methods*; D005260:Female; D005298:Fertility; D005307:Fertilization in Vitro; D006801:Humans; D007246:Infertility / Q000188:drug therapy; D009369:Neoplasms / Q000150:complications / Q000628:therapy; D009865:Oocytes / Q000166:cytology*; D010053:Ovary / Q000166:cytology* / Q000473:pathology*; D016649:Primary Ovarian Insufficiency / Q000628:therapy; D011878:Radiotherapy / Q000009:adverse effects; D012099:Reproductive Techniques; D016378:Tissue Transplantation / Q000379:methods*
D000970:Antineoplastic Agents