Embryo Cryopreservation and Thawing Information Packet

When excess embryos are present after an embryo transfer, these can be frozen and then  transferred in subsequent cycles, if the patient does not become pregnant.  This would save her from undergoing another oocyte retrieval procedure. She may also elect to have her embryos donated to another infertile couple.

Excess embryos are place with a cryoprotectant and aspirated into cryostraws, and then gradually frozen to a temperature of -196°C, and placed in liquid nitrogen. When the patient wants to transfer embryos that are in cryostorage, these can be thawed prior to or on the day of transfer, assessed for survival and development, and then transferred.