Freezing of embryos (Cryopreservation)

Number of embryos to be replaced

When a number of embryos are formed from the eggs collected, we still normally replace only one embryo in that cycle (under special circumstances, we may replace two). This is the policy of many IVF centres around Australia. It may be possible to freeze and store some embryos not replaced in the initial treatment cycle.

If pregnancy does not occur in the IVF cycle, your frozen embryos may be thawed and replaced in a later cycle; this is called a frozen embryo transfer (FET). This possibility will be discussed with you at the pre-treatment interview. Frozen embryos may be thawed and replaced at the appropriate time in any subsequent cycle, even several years later.

You should be aware that:

1. not all embryos are suitable for freezing; and,

2. not all embryos survive the freezing and thawing process.

If you do not become pregnant in the cycle of IVF, it is generally advised to wait at least one cycle before returning to have a frozen-thawed embryo replaced. If your menstrual cycles are normally regular, medication to stimulate the ovaries is not required in a cycle in which thawed embryos are replaced. It is only necessary to "track" that cycle for a few days prior to the expected day of ovulation, to find the optimal time to replace the embryos.

Embryos in storage

We know that the majority of couples will gladly consent to the freezing of embryos as it can provide them with more than one opportunity to achieve a pregnancy from their treatment cycle. However it is important to be aware that if you do consent to freezing you may have embryos left in storage that you do not need (where you have achieved the desired pregnancy and have a healthy baby for instance.)

The decision concerning what to do with embryos that you do not want yourself can be complex for many couples. We are happy to answer any questions you may have about this and if you need an in-depth discussion on this please contact our counsellor.

These embryos belong to both of you and any decisions, about their use or disposal, must be taken by both partners. We will keep them for you for up to ten years and would only dispose of them with your authorisation in writing. If, however, you wish to keep them beyond ten years, you are required to notify us in writing.