The Times January 06, 2006
Frozen eggs will allow women to put family life on iceBy 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 GuyÂ’s 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. That’s 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