The Times January 06, 2006
Frozen eggs will allow women to put family life on
ice
By Mark Henderson, Science Correspondent
WOMEN in their twenties will be freezing their eggs to delay
motherhood for social reasons within a decade, fertility
specialists predicted yesterday.
They said that recent advances had paved the way for a paradigm
shift in reproductive medicine that would help young women to
preserve their fertility until they had established their careers
or found the right partner.
The technology will soon make it simple for women to have a dozen
or more eggs collected and banked on ice while they are at their
fertile peak, Simon Fishel, of the Care fertility clinic in
Nottingham, said. These could be thawed once they were in their
late thirties or fortiess to give them a better chance to start a
family when their natural fertility would have declined.
Female fertility usually falls sharply after 35, yet the age of
motherhood in Britain is rising as social trends lead more women to
postpone trying for a first child. Women in their early 30s are now
having more babies than women in their late 20s, and the average
age of mothers has risen from 26 in 1985 to 29 today. The average
age of first motherhood is 27.
While the defrosting and implantation of frozen eggs has been legal
in Britain since 2000, and 23 clinics are licensed to carry it out,
the procedure is unreliable and is generally offered in only
extreme circumstances.
Only two British women, Helen Perry and Margaret McNamee, have
given birth using frozen eggs. Both chose the procedure because
they had religious objections to freezing IVF embryos that might
never be used. Other women who have stored eggs are cancer patients
whose treatment risked causing sterility.
Jennifer Rutansky, 34, became the first cancer patient to have a
baby from a frozen egg last year at a clinic in Florida. She used a
surrogate mother.
A new technique called vitrification has recently been shown to
deliver dramatic improvements to the freeze-thaw process, Dr Fishel
said, making it possible to store the eggs of many more
women.
We are approaching a defining paradigm shift in the area of
fertility preservation for females, he said. There are a lot of
women of reproductive age who are going to want to have a career,
and they are not going to be frightened off by being told they
should have children in their twenties.
When we get to the stage where freezing eggs is quite safe and
effective, there will be a significant proportion in our society
who will want their eggs frozen at a younger age. It may take
several years to come about, but I believe that will come, unless
there is a sea change in social attitudes that encourages women to
have children younger and give up their careers. This will come
within ten years, maybe sooner.
Virginia Bolton, consultant clinical embryologist at Guys
Hospital, London, said that careers were not the only consideration
that would encourage young women to freeze eggs.
More and more women are finding it harder and harder to find a
suitable partner, but want a family, she said. They are finding
themselves in their late thirties and without a partner, not
delaying motherhood because of a career. Thats when they start to
panic and worry about their biological clocks. This is not about
whimsical, selfish women who want to have life entirely on their
terms.
While it has long been possible to freeze sperm and embryos for use
in IVF, or to preserve the fertility of cancer patients who would
otherwise risk sterility because of chemotherapy, egg freezing is
much more complicated.
Eggs are much larger than sperm, many fewer of them are produced,
they are considerably more fragile and they contain more water.
When they are frozen this water forms ice crystals that readily
damage the egg when it is thawed. Although the first baby conceived
using a frozen egg was born in 1986, only about 200 more have been
born worldwide since.
Under the new vitrification procedure, developed by scientists in
Japan, Denmark and the US, moisture is removed from the egg before
it is frozen and an antifreeze chemical is added. Both steps
discourage the formation of ice crystals, as does
flash-freezing.
We are now seeing egg survival rates of about 95 per cent and a
pregnancy rate of about 25 per cent, Dr Fishel said. We were
looking at a success rate of no more than 5 per cent before, so
this means it could become a genuine option.
A woman wanting to have her eggs frozen in her late teens or early
twentiess would find the combined cost of drugs and egg storage is
about £2,200.
HOW IT WORKS
Woman in her early twenties, takes drugs to stimulate multiple egg
production
Eggs are frozen in liquid nitrogen
After the age of 35 she could use the frozen eggs to start a
family
Eggs would be thawed, with 95 per cent chance of survival, and
would be fertilised in vitro, with a 25 per cent chance of
success