Both egg and embryo freezing are available at Womens’ Hospital International and Fertility Centre.
Why freeze and store your eggs and embryos?
Eggs
You may wish to store your eggs for future use in treatment for a number of reasons, including if you: are about to undergo chemotherapy or radiotherapy require surgical removal of your ovarie face early menopause
You may wish to store your eggs for future use in treatment for a number of reasons, including if you:
- Are about to undergo chemotherapy or radiotherapy
- Require surgical removal of your ovaries
- Face early menopause
- Wish to postpone childbearing age until after 35
On rare occasions eggs can be frozen in an emergency, for example, when a semen sample can not be produced.
The main advantages of egg freezing are that partner or donor sperm is not required at this stage, so freezing can help preserve fertility in single women, and certain ethical issues relating to the storage and potential disposal of embryos are avoided.
However, there are several disadvantages too. Freezing human eggs is still a relatively new technique and therefore may involve as yet unidentified risks, such as increased risk of a congenitally abnormal baby. What’s more, thawing cryopreserved eggs is more expensive than thawing embryos because after thawing, eggs require fertilisation using ICSI.
Embryos
At WHI&FC, surplus embryos may be frozen after IVF treatment for use at a later date to create more siblings or if the treatment cycle was unsuccessful. Frozen-thawed embryos have a lower viability rate compared to ‘fresh’ cycles. However, the frozen embryo transfer (FET) is much less invasive.
What does egg freezing involve?
You will be required to have screening tests performed for HIV and hepatitis B and C before freezing and storage of your eggs. You must also attend a counselling session at the centreto discuss the implications of treatment. You will also be required to complete consent forms for freezing and storage of your eggs. These consent forms allow you to specify:
- What should happen to your eggs if you were to die or become unable to make decisions for yourself
- Whether the eggs are to be used for your own treatment only, or whether they can be donated for someone else’s treatment or for training
- Other conditions you may have for the use of your eggs
You may change or withdraw consent at any time, either before treatment or before the eggs are used in training.If this happens, your eggs will not be used. The process is similar to going through an IVF cycle, as you will have to take fertility drugs to stimulate the ovaries to produce follicles (which contain the eggs). The developing follicles are monitored and when they are large enough you will be required to go through the egg recovery procedure, where the follicles are carefully emptied to collect the eggs. For further information please refer to our IVF treatment page.
How are eggs and embryos frozen?
Only mature eggs will be frozen. At WHI&FC, eggs and embryos are frozen by vitrification – a process whereby the solution containing the eggs is cooled so quickly that the structure of the water molecules doesn’t have time to form ice crystals and instantaneously solidifies into a glass-like structure.
How long can my eggs and embryos be stored for?
The standard storage period for eggs and embryos is ten years from the date of freeze, up to a maximum of 55 years. If you have frozen eggs or embryos at the centre it is your responsibility to keep in touch and notify the centre of any changes in your contact details. There will be an annual fee for storage of eggs and embryos at our centre. If you fail to pay the storage charges, or if we are unable to contact you when the storage period is coming to an end, we may remove your eggs/embryos from storage and allow them to perish. Further details are set out in our terms and conditions of storage, and you will be asked to complete a ‘Consent to the preservation and storage of eggs by freezing’ form.
What is my chance of having a baby with frozen eggsand embryos?
Eggs
It is difficult to assess the chances of a successful pregnancy using frozen-thawed eggs.
Vitrification has shown to yield potentially far more successful results in the freezing of eggs. It has also been suggested that vitrification may be less traumatic for eggs and may have less effect on their physiology.
Embryos
As with egg freezing, at EHI&FC, embryos are cryopreserved using vitrification. Vitrification of embryos is starting to become more common worldwide as more IVF laboratories start to implement this technique. Although the number of frozen embryos is still low, there seems to be a marked increase in the survival rate of vitrified-thawed embryos compared to that of embryos cryopreserved using the slow freeze method.
What are the risks of egg freezing and storage?
It is important that you are fully aware of all the potential problems involved prior to going ahead with treatment.The centre staff will explain the risks and you willbe given an opportunity to ask questions. Egg freezing is still a relatively new technique and not all eggs will survive the freezing and thawing process orbecome fertilised.