Approximately 50% of patients have extra embryos following their IVF cycle. These embryos can be saved for future use, providing the opportunity for additional attempts at pregnancy from a single IVF cycle. Embryo freezing or cryopreservation allows embryos to be stored by cooling them to a very low temperature (-196oC) and storing them in liquid nitrogen. During the freezing process, the embryos are placed in solutions that gradually remove the water from their cells. This protects them from damaging ice crystal formation during freezing.

When thawed, they are placed in a different series of solutions to add water back to the cells. These thawed embryos can then be transferred into the uterus during a frozen embryo transfer (FET) cycle for another attempt at pregnancy, without having to undergo the entire IVF cycle. By this means the cost of treatment will be significantly reduced and without the risks of oocyte retrieval or ovarian hyperstimulation.

Vitrification is a method of cryopreservation that allows for ultra-rapid cooling of embryos, preventing the formation of damaging ice crystals. Vitrified embryos have better post-thaw survival rates and can result in higher pregnancy and live birth rates.

Not all patients will have extra embryos for cryopreservation. Only good quality embryos are frozen as poorer quality embryos do not survive the freezing thaw cycle.

All precautions are taken to safeguard cryopreserved embryos and gametes (eggs and sperm).  They are stored in special liquid nitrogen tanks that are alarmed 24/7 to detect any fluctuations in temperature and liquid nitrogen levels are checked daily to ensure appropriate levels are maintained, the development of these additional security levels and backup protocols have been created to ensure the highest standard of safety measures are in place.  These processes used by the lab have been extensively assessed by Accreditation Canada.  Our staff are considered to be providing an essential service by Alberta Health Services and are able to access the clinic daily to perform all the necessary tasks even if a lockdown of the city is declared.

Check out our frequently asked questions (FAQ’s) for further information regarding cryostorage.