Freezing - introduction
Freezing
There are three freezing options which may help preserve a woman’s fertility:
Eggs, embryos and ovarian tissues can be frozen and stored for many years. When the time is right, they can then be thawed and used for a pregnancy after cancer treatment has been completed.
Different methods of freezing are available to preserve eggs, embryos and ovarian tissue. Cryopreservation is a method of ‘slow freezing’. Vitrification is a newer method of ‘fast or flash freezing’. This method has been shown to improve the chance of eggs and embryos surviving the thawing process and make the pregnancy success rate higher.
Some women, if they have a male partner, may be able to freeze both eggs and embryos. They may have more fertility options available to them in the future after their cancer treatment.
Ovarian tissue freezing is a new method of fertility preservation. This could be another option for women with no male partner.
Ovarian Tissue Freezing
Ovarian tissue which contains a large number of immature eggs is removed and frozen. After cancer treatment, the tissue can then be put back into the body to allow the eggs to develop. It is a newer method of fertility preservation and not available in all fertility clinics yet. It can be used immediately before and during chemotherapy.
Who is it for?
Women who wish to preserve their fertility and:
- Do not have time to freeze embryos or eggs.
- Who cannot use fertility drugs.
After the ovarian tissue is replaced, it can restore your normal hormone production and cycles, and may allow the chance of getting pregnant naturally. It is also suitable for girls who have not reached puberty.
Careful consideration is required in women with a blood cancer such as leukaemia. This is because there is a chance of putting cancer cells back in the body with the frozen ovarian tissue.
What does it involve?
You will need to have key hole surgery under a general anaesthetic. One ovary or part of an ovary will be removed so that the outer layer (the cortex) that contains the immature eggs, can be frozen. Women may go home the same day as the procedure.
As ovarian tissue freezing only involves the woman, there is no need for your partner or parents’ consent to use the stored tissue in the future. There is no upper limit for how long frozen ovarian tissue can be stored.
What is the chance of having a baby after ovarian tissue freezing?
It is difficult to be certain how likely it is that ovarian tissue freezing will result in a live birth. As this is a newer treatment, the number of cancer patients who have used their frozen tissue to have a baby is low. This data shows the chance that ovarian tissue freezing will help a woman to have a baby is around 30 in 100 (30%). For more information on national average success rates and the number of successful live births for each licensed fertility clinic visit the HFEA website www.hfea.gov.uk.
Will this option affect the health of the baby?
No, the data suggests that the health of a baby born using frozen ovarian tissue will not be affected.
Are there any side effects of the treatment used in ovarian tissue freezing?
There may be a chance of bleeding and infection and of damage to the bladder and bowel during the surgery to remove the ovarian tissue.
Will this option delay the start of my cancer treatment?
The procedure is mostly carried out during one day (with no overnight stay in hospital) and will not cause any delays to cancer treatment.
Will this option affect my chances of the cancer coming back?
In some types of cancer, such as leukaemia, there could be a chance of ovarian tissue being contaminated with cancer cells. There are no cases of a cancer coming back from the use of ovarian tissue that has been put back into the body.
You may find it useful to write down what you like about this option and what worries you about this option.
These notes may help you talk about whether or not this option is best for you with your cancer care team and fertility care team, partner, family and friends.
