Fertility preservation for female cancer patients

 

Why is the ovary affected?

How many eggs are there in the ovary?

What can be done to give me a chance of fertility?

In Vitro Fertilisation (IVF)

Oocyte donation

Developing new options

Frequently asked questions

 

 

Some forms of medical treatment, particularly chemotherapy and radiotherapy, can have an adverse effect on fertility in women. This generally occurs as a result of a toxic effect on the ovary leading to permanent death of the eggs (oocytes) in the ovary.

 

Why is the ovary affected?

 

When girls are born, they have all the eggs that they will ever have and then continue to use them up through the rest of their life. Unlike men who continually make sperm throughout their lifetime, women cannot make any new eggs. Therefore any eggs, which are lost or damaged through medical treatment, can never be replaced.

 

How many eggs are there in the ovary?

 

As shown in the figure, the eggs in the ovary are in three forms:!cid_6DF31914-72E6-44DC-A2FE-CCFA6D659CDE

  • Immature eggs (primordial oocytes). There are many thousands of these stored within the ovary waiting to be released. A reliable method of maturing these eggs is still being researched. However, immature eggs can be satisfactorily frozen in the tissue in case of any future developments.
  • Developing eggs. There are approximately 5 to 20 of these in the ovaries at any one time. These eggs are partially mature and if removed from the ovary at this stage may be matured by culture in the laboratory for several days. This process of partial ‘in vitro maturation’ has been successful in producing mature eggs, which will fertilise in the laboratory and these fertilised eggs have resulted in successful pregnancies in a small number of women. However, these matured eggs cannot be easily frozen.
  • Mature eggs. The ovary naturally produces only 1 (or occasionally 2) mature eggs in the middle of each menstrual cycle. This is all that is normally required for pregnancy. In theory, this mature egg could be collected for storage just before ovulation. However, this would provide only a very tiny chance of a future pregnancy and is generally regarded as insufficient to make single egg collection and storage worthwhile.

Hormone treatment given by daily injection for about 12 days can be used to allow several eggs to become mature for collection at one time. This is a usual part of In Vitro Fertilisation (IVF) treatment. Mature eggs can be fertilised with the partner’s semen and the fertilised egg (embryo) can be frozen and stored. Mature eggs can also be frozen and later thawed before fertilisation in the laboratory.

 

What can be done to give me a chance of fertility?

Chemotherapy and radiotherapy treatment can harm all 3 of these egg types and therefore may cause irreversible fertility. At present, there is unfortunately no proven way to protect the ovaries against the effects of these treatments. The only treatment that is currently readily available and which offers a reasonable chance of future pregnancy, is to undertake In Vitro Fertilisation (IVF) and store the resulting fertilised embryos.

 

In Vitro Fertilisation (IVF)

 

The aim of an IVF procedure is to collect as many mature eggs as possible then fertilise them with your partner’s sperm to create embryos. Embryos can be frozen and therefore stored for as long as you need them. For more information on how the IVF procedure works, click here. The chance of a successful pregnancy for any 1 cycle of treatment using these embryos is only about 30%.

It is therefore important to remember that this form of treatment will give you a CHANCE of success but quite clearly does not guarantee pregnancy.

The IVF procedure takes approximately 2 weeks to complete. Therefore you need to be able to safely delay chemotherapy or radiotherapy treatment for 2 weeks. Your specialist will advise you if this is possible. For some forms of cancer treatment delay or ovarian stimulation with hormones is not advisable.

 

Oocyte donation

 

If your fertility has already been compromised by chemotherapy or radiotherapy treatment, you may be able to achieve a pregnancy if another woman donates her eggs to you. The donor would have to go through an IVF treatment cycle to have her eggs collected .

The collected eggs would be fertilised with your partner’s sperm and the embryos transferred (implanted) to you at an appropriate time. This option has a lot of ethical and emotional consequences for both you and the egg donor. Careful thought and counselling is advised.

 

Developing new options

 

Ovarian tissue storage

 

By having a small piece of your ovary collected now and stored deep-frozen, you may be able to use it at a later date in one of two ways.

1. Complete oocyte maturation in the laboratory. This is being researched around the world, however is not available as yet.

2. Surgical re-implantation of the removed piece. It is possible to surgically replace the small piece of ovary once the chemotherapy or radiotherapy treatment has been completed. This has now been used successfully in 8 women with the birth of 11 healthy babies so far (December 2009).

 

Frequently asked questions

 

What are the chances of my ovaries being damaged by treatment?

 

This is variable and depends on your age and the type of cancer or other medical treatment you require. Return of normal menstrual and reproductive function can vary. Women whose periods stop altogether after cancer treatment have generally had fairly severe damage to the ovary while women whose periods continue normally have had less or even no damage to the ovary. However even these women may later have an earlier menopause.

 

Does the damage to my eggs have any other effects on my health?

 

Yes. Your ovaries need the eggs in order to make the female hormone oestrogen. Therefore if your eggs are lost or damaged through medical treatment, your hormone levels will drop considerably and you may experience early menopause. Relief of Menopause symptoms, such as hot flushes and night sweats can be obtained by taking hormone replacement therapy. In cases where oestrogen hormone replacement therapy cannot be used, such as breast cancer, a number of other options can be used to relieve the symptoms of a premature menopause. In the longer term, a premature menopause may increase the risk of heart disease and the bone disease, osteoporosis. To prevent this, your doctor may advise you to take hormone replacement therapy up to the time that your menopause would have occurred naturally.

 

Is there a risk of transmitting cancer cells if surgical re-implantation is carried out?

 

This may unfortunately be a possibility. Previous work in mice demonstrated that some forms of bloodborne cancer could come back as a result of surgical reimplantation of a piece of ovarian tissue. Surgical reimplantation of ovarian tissue would not be recommended in a woman with a bloodborne cancer (e.g. lymphoma or leukemia) unless this risk could be removed. The situation for a solid cancer in another part of the body (e.g. breast cancer) remains unclear. It may be possible in the future to use genetic tests to screen ovarian tissues for cancer cells prior to replacement of the biopsy.

 

How long can the ovarian tissue be kept in storage?

 

The ovarian tissue can be stored for as long as you need. Unfortunately tissue can be damaged by the freezing and by the thawing processes. However, the risk of such damage is not increased by the length of time spent in freeze-storage. The tissue can therefore be safely left for years if necessary. In addition, we know that children who are born from embryos that have been frozen appear to have a perfectly normal development in later life.

 

Are there any costs for these services?

 

Storage of tissues and eggs (to preserve your options for later) is provided without any charge or commitment.We will contact you every 12 months to check whether you still wish to continue the storage. Westmead Fertility Centre (WFC) may need to charge for complicated fertility treatments. Full details are available from WFC on request.

Attend an information seminar
Westmead ButtonWestmead Doctor, IVF clinic
When: Wednesday, November 8, 2017
Time: 5:30pm for 6:00pm start
Where: Westmead Fertility Centre
Cost: Free