Egg donors are hard to come by and the demand far exceeds the supply. Egg sharing is a unique situation in which the egg provider is both an IVF patient and an egg donor. Not only does egg sharing increase the availability of donor eggs for a potential egg recipient, but also allows the egg provider to receive her own IVF treatment at a very much reduced cost.

Who can be an egg sharer?

The basic criteria as to who can be an egg provider are the same as for egg donation. But it is obviously in both the egg provider's and egg recipient's interests that sufficient eggs of good quality can be produced for sharing. The egg recipient will be understandably concerned that she does not receive poor quality eggs from a provider who has her own fertility problems. We therefore use very strict additional eligibility criteria when it comes to egg sharing. A potential egg sharer would be excluded from entering our egg share programme if:

• At previous IVF less than 10 eggs were collected on each occasion
• At a previous IVF attempt there was a failure of eggs to fertilise or a failure to reach the point of embryo transfer
• The FSH (follicle stimulating hormone) level taken during the early days of the menstrual cycle was raised indicating that it might be difficult to stimulate adequate eggs to grow
• She only had one ovary
• She had a history of polycystic ovary syndrome
• She had moderate / severe endometriosis
• There was a prolonged history of "unexplained" infertility

This list will exclude the vast majority of potential egg providers in whom one could predict difficulty in recruiting an adequate number of good quality eggs for sharing. It means that the egg sharers we use will be seeking IVF for themselves because they have blocked fallopian tubes, a short history of "unexplained" infertility, or there are significant male infertility factors. None of these should affect egg quality.

What are the screening tests for the egg provider?

The egg provider is screened as an egg donor and her partner is screened in the same way as the partner of any patient undergoing IVF.

What are the egg provider's expenses?

She will pay for her consultations, screening tests, drugs and approximately 40% of the cost of an IVF cycle. There will be no additional charge for counselling, monitoring during treatment, egg retrieval, embryology or embryo transfer.

If the provider's own treatment required surgical retrieval of sperm, ICSI, blastocyst transfer, cryopreservation of embryos or frozen embryo transfer, she would pay these costs herself. It would be unreasonable to pass these charges across to the recipient couple.

How do the egg share arrangements work?

Our egg share programme guarantees that an egg recipient will receive at least four eggs.

Eggs are shared equally between the provider and recipient so a minimum of eight eggs is required for sharing. The egg provider will be allocated the extra egg when an odd number of eggs are retrieved (e.g. if there are nine eggs, the provider receives five and the recipient receives four).

While it is expected that the majority of egg providers will produce more that eleven eggs, this is not always the case. It is essential that you have a clear understanding of the arrangements if fewer eggs are collected than the minimum required for sharing. These will be discussed in depth and are described in detail in our egg sharing information booklets.

How do I join the egg share programme as an egg provider?

You should be referred by your General Practitioner or Gynaecologist giving full details of your past medical history and infertility history. This should include the results of any investigations that have been performed and details of treatments you have already received.

If you have previously been treated by IVF or ICSI we would need to have full details of the drug stimulation that was used, the number of eggs that were retrieved and the outcome with regard to the number and quality of the resulting embryos.

You will both have an initial consultation with one of our consultant specialists. A detailed medical, infertility and family history is taken. Unless it has been recently performed, an examination is carried out too. If there are no obvious exclusions to you becoming an egg provider as listed above, the stages of how you will be assessed for suitability to join the egg share programme will be discussed.

The next step is to have a hormone-screening test. This blood test is taken between day 2 and 4 of a natural menstrual cycle either the centre or through your own GP.

With your consent we will write to your GP asking if there is anything in your own or your family medical history that would make it inadvisable for you to become a donor.

Because both of you are hoping to become parents by IVF, you will also both be provided with a Welfare of Child questionnaire to complete This is to ensure that there are no medical or social reasons why either of you might be unsuitable to have treatment, as by law we are required to consider anything that might adversely affect the welfare of any resulting child or existing child.

If the hormone profile is satisfactory, an appointment is arranged for you both to see our very experienced counsellor who will discuss your views about the implications of egg sharing as well as the legal and ethical aspects of donating eggs. For example, there are implications of remaining childless after your donation and of not knowing whether the other couple that has received your eggs has succeeded or not.

There are also implications of there possibly being half-siblings of a similar age resulting from treatment.

The counsellor will discuss all the issues and implications of becoming an egg provider. Whatever you discuss with the counsellor will remain confidential. She will either indicate to us that there is no problem preventing us proceeding or that there are still issues that she needs to resolve with you. A different counsellor is used for the recipient of your eggs.

The next stage is to see our consultant once more. The remaining blood tests are set up and arrangements are made for your partner to provide a sperm sample for our embryologist so that this can be assessed for IVF or ICSI.

When the results of all the preliminary tests are available, you will have a full planning session with our consultant who will discuss every aspect of your own IVF treatment and egg sharing and the "timetable" of the procedure. You will be asked to sign consent forms as an egg donor as well as consent forms for your own IVF treatment cycle.

There may then be a lull until a suitable recipient is matched with you and the recipient's tests etc are sorted out.

What happens if I change my mind?

Before you even begin the treatment cycle, you will have been very fully informed on all aspects of your planned egg donation. Your decision as to whether or not to proceed with egg sharing will therefore have been made on the basis of having the fullest possible information.

You may very well decide that this form of treatment is not for you. In that case we will thank you for the interest you have shown in our egg sharing programme and part amicably.

You can change your mind at any time without any fear of recrimination. If this should occur before the treatment cycle begins, you will only bear the costs of your consultations and tests to that point. In what we hope would be the very unlikely event of your changing your mind during the actual treatment cycle, there will be no refund made of the charges you will have paid prior to the treatment cycle commencing.

If you decide to keep all the eggs for yourself, even though eight or more have been obtained, you will then need to pay the full cost of the IVF treatment cycle.

Under the Human Fertilisation & Embryology Act (1990), as the egg provider, you may at any time vary or withdraw your consent altogether up to the time that an embryo containing your donated egg is used. This also applies to such embryos that have been frozen and stored for future use by the recipient.