Egg-sharing does not damage a
donor’s own chance of a baby say UK researchers
Women who take part in egg
sharing programmes run by fertility clinics are not
compromising their chance of having a baby by donating some
of their eggs, according to UK research published today
(Thursday 30 October) in Europe's leading reproductive
medicine journal Human Reproduction[1].
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.
