Embryo cryopreservation

What is embryo cryopreservation?

During an IVF treatment cycle, the ovaries are stimulated to produce more than one egg to maximise the chance of success. Since no more than one or two embryos are usually transferred during a treatment cycle there may be spare embryos remaining after treatment. It is possible for these spare embryos to be frozen, stored, and transferred during a subsequent treatment cycle with the advantage of fewer drugs and a much simpler treatment.

The process of freezing is called cryopreservation.

What are the benefits of cryopreservation?

A frozen embryo can be used in a future cycle without having to undergo the preliminary drug treatment and surgery. The treatment cycle is therefore much simpler for the patient and if you are self-funding the cost will be much less than a full IVF treatment cycle.

The procedure

Any embryos remaining after the process of embryo transfer are assessed for their suitability for cryopreservation. Embryos of suitable quality, and those at the correct stage of their development on the day of transfer, i.e. those most likely to survive the cryopreservation process, are selected for cryopreservation.

Frozen embryos may be kept in storage for up to ten years (the statutory storage period) although in some specific circumstances they may be stored for longer than this. There will usually be a fee for the ongoing storage of cryopreserved embryos and your clinic will make you aware of this before you consent to this procedure.

For more information, and if you have any queries, speak to your consultant.


Consent forms from The Human Fertilisation and Embryology Authority (HFEA) will need to be completed and signed so that the intended future use of any cryopreserved embryos is correctly recorded.

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