Delivering embryos following 10 years of cryopreservation, using unpaired freeze/thaw techniques: A case report.

Although frozen embryo transfer is a widely established route for assisted reproduction, successful frozen embryo transfer using embryos that have undergone long term cryopreservation remains relatively unexplored, and its efficacy remains a matter of some debate. This case report describes two successful frozen embryo transfer conceptions in the same patient, one after 3 months of cryopreservation and the second 10 years after cryopreservation. These embryos were cryopreserved using the slow freezing technique and were thawed using an unpaired technique (ultra-rapid warming) after 10 years of storage.