The Lister Fertility Clinic in London, a private clinic that has been running a formal egg sharing scheme since January 1998[2], has evaluated 276 egg sharing cycles involving 192 women who agreed to share their eggs, 274 recipient cycles involving 246 women who received eggs and 1,098 non-sharing standard IVF or ICSI cycles involving 718 women.
The participants were divided into three groups – egg sharers, non-egg sharers aged under 36 and recipients. The researchers evaluated the doses and duration of drugs needed for ovarian stimulation, the numbers of eggs collected and donated, and the fertilisation, pregnancy and live birth rates.
Clinic director and research team leader, Mr Hossam I Abdalla, said: "We found no statistically significant difference in the three groups. The egg sharers achieved a pregnancy rate of 42% and a live birth rate of 33%, the non-egg sharers achieved a pregnancy rate of 40% and a live birth rate of 30.9%, and the recipients achieved a pregnancy rate of 41.4% and a live birth rate of 28.6%."
The number of eggs collected, the number of mature follicles and the amount of stimulating hormone (gonadotrophin) used was not significantly different between the egg sharing women and the non-egg sharing women. In addition, the average number of embryos transferred and the mean numbers of eggs allocated between egg sharers and recipients was not statistically different.
"Up to now, there has been no research in the UK carried out with large numbers of patients to ensure that the egg sharing programme is not detrimental to egg sharers and/or to the outcome of recipients' treatment compared with standard IVF or ICSI," said Mr Abdalla.
An important additional finding was that there was no evidence to back up a theoretical risk that the donors may have an increased chance of the potentially dangerous condition of ovarian hyperstimulation syndrome – a condition where the ovaries go into overdrive and produce too many follicles and eggs as a result of the hormones given to prepare them for fertility treatment.
"The premise was that to have enough eggs for egg sharing, doctors may over stimulate the donors' ovaries," said Mr Abdalla. "But, we provided the donors with the standard drug regimen given to all IVF patients of a similar age and there was no increased incidence of ovarian hyperstimulation, of drug dosage or of the numbers of eggs produced compared with standard IVF patients."
He said that two previous studies had demonstrated lower pregnancy rates, but they had a smaller number of patients and there may have been a slight bias towards recipients in egg allocation. The present study had insisted that donors had at least the first four eggs so that there was a decent number of eggs for the donor's own treatment.
"Our view is that for successful egg sharing the sharer should always be given priority and have the first call on her eggs without any undue pressure. I believe that is the primary reason for the success of our programme."
Mr Abdalla said that egg sharing was a constructive way of solving the problem of shortage of eggs. So, it was a reassuring finding that patients who took part in a programme and provided a valuable source of donor eggs were not compromising their own chances or putting themselves at risk of additional complications.
However, he said that for egg sharing to be successful it was essential that the programme gave the women taking part all the advice and support that is provided for fertility patients and that donors always had priority in terms of their treatment and the first call on their eggs.
A study examining the psychological and emotional impact of the programme was also under way. "We need to know how a patient would feel if they did not fall pregnant and the recipient does, or vice-versa. There is potential here for joy, happiness, sadness and other emotions. So, it is particularly important to follow these patients up and we are currently providing an extensive questionnaire to all of our egg sharers." The results of this study should be available next year.
[1] Does egg-sharing compromise the chance of donors or recipients achieving a live birth? Human Reproduction. Vol 18. No. 11. pp 2363-2367.
[2] The Lister Fertility Clinic has been providing egg donation since 1988 with sporadic cases of egg sharing. A pilot group on egg sharing started in July 1997 and the programme was properly established from January 1998. About 5% of the clinics total cycles of assisted conception involve egg sharing. Egg sharers get reduced cost cycles. The only charge is £500 towards medications. The recipients do not pay for the donor's treatment, but pay overall charges similar to the cost of an IVF cycle. So effectively, two patients are treated for the cost of one treatment cycle. There is no obligation between the sharer and the recipient. The sharer can withdraw at any time and has primary claim on her eggs without extra cost. The egg sharer who is unsuccessful in conceiving, can try up 3 times, sometimes more.
According to the Human Fertilisation and Embryology Authority (HFEA) 45 out of the UK's 95 fertility treatment centres have egg sharing programmes.
Notes:
1 PDF version of this press release and full embargoed text of the paper with complete results can be found from 09:00hrs London time Monday 27 October
http://www3.oup.co.uk/eshre/press-release/nov203.pdf
or is available from Margaret Willson.
2 Human Reproduction is a monthly journal of the European Society of Human Reproduction and Embryology (ESHRE). Please acknowledge Human Reproduction as a source. Dr Helen Beard, Managing Editor. Tel: 44-195-421-2404 Email: beardh@humanreproduction.co.uk
3 ESHRE's website is: http://www.eshre.com
4 Abstracts of other papers in ESHRE's three journals: Human Reproduction, Molecular Human Reproduction & Human Reproduction Update can be accessed post embargo from http://www3.oup.co.uk/eshre/
Full text of papers available on request from Margaret Willson.
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