embryo freezing

Good quality embryos that are not transferred to the uterus may be frozen and stored at RMA. These embryos can be thawed and transferred in a future freeze-thaw cycle.


Embryo freezing involves the careful addition of media containing cryoprotectants to allow the embryos to be cooled to very low temperatures and stored in liquid nitrogen (-196°C).


When the embryos are thawed the cryoprotectants are slowly removed from the embryos as they are warmed. Surviving embryos can then be transferred to the uterus.

It is expected that approximately 70-80% of frozen embryos will thaw successfully.

The advantages of cryopreservation of embryos are:

i) It allows an increase in the pregnancy rate while minimizing the number of times the ovaries undergo stimulation
ii) It minimizes the number of hospital attendances for egg pick up procedures
iii) It may lessens the cost of achieving a pregnancy

The disadvantages of cryopreservation are:

i) If you become pregnant and still have embryos in storage, you will need to decide what to do with the embryos at a later date
ii) Legal problems may occur when embryos are in storage and death or divorce occurs. This is covered in our consent form for your guidance and you will need to predetermine the fate of your frozen embryos when you sign your consent.