Cryopreservation of oocytes is a technique that allows women to preserve fertility for the purpose of using these oocytes at a later date or to safeguard fertility due to medical reasons.
New York University Fertility Center and New York University School of Medicine conducted a research to determine if long-term cryopreservation of oocytes affects oocyte developmental competence, live-birth rates and blastocyst aneuploidy.
In this research, a total of 33 patients cryopreserved their oocytes for various reasons. Only one patient who was not included in this research due to the fact that, after oocyte thaw, there was no blastocyst available for biopsy. These patients thawed their 475 oocytes cryopreserved between June 2006 and February 2014 for 3.5 years on average. Between December 2011 and July 2014, cryopreserved oocytes underwent oocyte thaw, blastocyst culture, trophectoderm biopsy and preimplantation genetic screening with array comparative genomic hybridization.
Results obtained from cryopreserved oocytes compared to fresh oocytes:
- Same rate of oocyte fertilization
- Same rate of aneuploidy
- Significantly lower blastocyst formation rate
- Same rate of implantation
- Same live-birth rate
The 80.4% of oocytes survived oocyte thaw and achieved blastocyst formation with rates similar to blastocysts coming from fresh oocytes. In conclusion, it is supported that oocyte cryopreservation is safe and successful.