Hailed as a breakthrough for women suffering from fertility problems, the revolutionary technique which enables eggs to be frozen for use at a later date is alarming experts who fear the emergence of lifestyle genetics. Sophie Goodchild reports

Scientists have successfully created Britain's first human twins through a revolutionary fertility treatment using frozen human eggs.

Scientists have successfully created Britain's first human twins through a revolutionary fertility treatment using frozen human eggs.

This pregnancy, involving a 36-year-old woman, is being heralded as a milestone in the advancement of medical science and is an important breakthrough for women suffering from fertility problems.

Among those who could be helped to conceive are cancer patients undergoing chemo-therapy and women facing the loss of their ovaries because of medical conditions.

More controversially, the treatment also increases the options for single career women who want to preserve their fertility by freezing eggs for the future.

Clinics were first allowed to thaw frozen eggs and use them to create babies in 2000. Since then, there has been only one documented case of a woman in this country giving birth using her own frozen eggs. Helen Perry became the mother of baby Emily in June 2002 after being treated at Midland Fertility Services, near Walsall.

This is the same clinic where the 36-year-old mother-to-be, who wants to remain anonymous at this stage, conceived her twins more than five months ago.

She already has one child and approached Midland Fertility Services because she hoped to conceive again. For ethical reasons, she did not want traditional IVF, which can involve creating extra embryos that may be frozen or discarded.

Instead, doctors used the eggs produced from her first fertility treatment. They were deep frozen for 18 months, protected with a chemical solution. They were then defrosted and fertilised with her husband's sperm, using a very fine needle, and implanted back into the uterus.

Only around 200 babies have been born worldwide through egg freezing, compared with more than a million children created through conventional assisted reproduction techniques.

The reason for the low success rate is that unfertilised eggs are fragile. Ice crystals can form inside and damage the delicate contents. This is why many clinics consider the treatment too risky.

In addition, experts, including the fertility pioneer Lord Winston, have expressed concerns about the physical and mental development of "frozen egg" babies.

A report by the Medical Research Council, published last year, listed a number of areas where doctors remain "largely ignorant" of the long-term effects of treatment.

Dr Gillian Lockwood, medical director of Midland Fertility Services, said egg- freezing had "come of age" and techniques had vastly improved. "It shows that little Emily [Perry] is not a lucky fluke - this treatment offers patients a real chance of giving birth to their own genetic child," said Dr Lockwood.

"Assisted conception children should be monitored, but there is no evidence of any problems."

Dr Lockwood said it was better for women who delayed motherhood to use their own "young" eggs. "It is heart-breaking giving fertility treatment to someone over 40 and we mustn't deprive these women of having a healthy baby," she said. "I would rather treat a woman of 42 with eggs she had frozen at 32, than use her 42-year-old eggs, because of the risk of miscarriage and abnormalities.

"You can have Botox as much as you want, but it will do nothing to reduce the age of your reproductive system."

The Human Fertilisation and Embryology Authority, which regulates assisted reproduction, said the success rates of egg freezing were beginning to improve. "But they are not all that great," said a spokesman. "In terms of any doubts about egg-freezing, there are no known dangers we have come across."

A woman is the legal owner of her frozen eggs but this is not the case with embryos. There have already been a number of high-profile legal disputes over the ownership of frozen embryos because consent must be given by both the woman and the man at every stage of the process under current fertility laws.

Last year, a court ruled that a woman who was left infertile after cancer treatment, was not entitled to use frozen embryos fertilised by her former fiancé. Natallie Evans lost her case after her ex-boyfriend decided he did not want her to use the embryos.

Other medical experts have welcomed the potential benefits of egg freezing. Dr Susan Carr, from the Royal College of Obstetricians and Gynaecologists, said any development in reproduction was positive "as long as these treatments are based on clinical evidence".

Dr Carr, a consultant in family planning and reproductive health at the Sandyford Initiative in Glasgow, added: "It's an enormous advancement to be able to offer women the opportunity of having their eggs frozen.

"To stop treatment like this because some people disprove for social reasons, is to deprive other women who may have suffered from cancer of the chance to have a genetic child."

And meet Emily, Britain's first 'frozen baby'...

Helen Perry, 38, made medical history when she gave birth to her daughter Emily nearly three years ago. The 7lb 13oz baby was the first in this country to be born from her mother's frozen egg.

Mrs Perry and her husband Lee, 39, had spent years trying unsuccessfully to have a baby and had been on an NHS waiting list for IVF for four years before contacting Midland Fertility Services, which is licensed to provide egg-freezing treatment. At the time, Mrs Perry, who lives in Wolverhampton, says that she and her husband were not aware they were creating medical history. "I wanted children since I was very little, and wanted children more than I wanted to get married," she says. "There were no medical problems with my family, but I was not getting pregnant."

Eventually, doctors discovered that an emergency appendix operation when she was seven had resulted in blocked fallopian tubes, giving her no hope of conceiving naturally. Mrs Perry did undergo IVF treatment but it was then discovered that she was at risk of developing a potentially fatal condition called ovarian hyperstimulation syndrome. So the clinical team at Midland Fertility Services froze the unfertilised eggs that had been extracted during the IVF attempt, and waited until her ovaries had recovered before thawing the eggs and injecting them with her husband's sperm. A first attempt at pregnancy failed but the second was successful.

"We knew it was a new process but we did not realise we were creating history," says Mrs Perry, who celebrates her 20th wedding anniversary this year.

Experts have expressed concern about the development of children conceived as a result of egg freezing. However, Emily has above-average language skills and is a "very lively and happy little girl".

Mrs Perry has not ruled out having more children. "Although I'm approaching 40, my eggs are only 35."

So would she advise other couples to consider egg-freezing? "Definitely. We are thrilled to bits and the clinic was brilliant. Anything that helps people have a chance of having a baby when they desperately want one, is worth it."