Human oocyte cryopreservation.
OBJECTIVE
This review summarized the clinical breakthroughs in the human oocyte cryopreservation field in the past 2 years and gave special emphasis on the role of vitrification method. Human oocyte cryopreservation is an attractive strategy to preserve female fertility, as it offers more opportunities to the future destination of the female gametes and also raises fewer legal and ethical questions compared with embryo cryopreservation. It became promising in recent years because of dramatic improvement in cryopreservation technologies. Human oocyte cryopreservation would not become a clinical routine until the availability of reliable cryopreservation methods and long-term follow-up results of the babies born by this technique.


RESULTS
Oocyte cryopreservation produced very exciting results with pregnancy and implantation rates comparable to embryo cryopreservation and in some cases comparable to fresh in-vitro fertilization cycles with both modified slow-freezing and vitrification methods. A cancer patient conceived and delivered her own babies by this technology after recovery from the disease. Oocyte cryopreservation became a new focus in assisted reproductive technology.


CONCLUSIONS
We witnessed the advanced development of human oocyte cryopreservation in the past years because of increasing demand, medically, legally and ethically, and also because of the dramatic improvement of the freezing technique. There is still a long way to go to integrate it into a routine clinical procedure to benefit more patients and encourage clinicians to follow the standard protocols.
Tao
Tao
T
Toronto Institute for Reproductive Medicine, Toronto, Canada. tao_tao_1998@yahoo.com
Zhang
Wenling
W
Del Valle
Alfonso
A
D000293:Adolescent; D000328:Adult; D002648:Child; D015925:Cryopreservation / Q000379:methods*; D003451:Cryoprotective Agents; D005260:Female; D006801:Humans; D009865:Oocytes; D055815:Young Adult
D003451:Cryoprotective Agents