Frozen ovary banks to offer childbirth in later life

Scientists have successfully "banked" frozen ovaries for the first time as part of a transplant experiment that could reverse the menopause of women who would otherwise be sterile after cancer treatment.

The breakthrough could also open the door to an era when young professional women could have one of their ovaries stored in a tissue bank for 20 years or more to prolong their fertility well beyond the normal onset of the menopause.

Although scientists had limited success in transplanting slices or strips of ovarian tissue, they have not – until now – managed to transplant a whole ovary that has been deep frozen.

The experiment was done on laboratory rats but the British-born scientist who led the research said yesterday that he expects the first clinical trials on patients to begin within three years.

Professor Roger Gosden, the scientific director of the Jones Institute for Reproductive Medicine at the Eastern Virginia Medical School in Norfolk, Virginia, said the immediate goal was to help young women having medical treatment who were at risk of becoming infertile.

He said: "The goal of transplanting the whole ovary was really to try to restore the natural state in a way that we probably couldn't do with strips of ovarian tissue. Strips of tissue can work quite well in animals, but it hasn't worked so well in humans. Past attempts have been short-lived but at least they have demonstrated proof of principle."

The study, reported in the journal Nature today, involved freezing eight complete rat ovaries in liquid nitrogen and transplanting them into genetically identical rats. Four of the animals had their fertility restored and one became pregnant with two healthy foetuses.

Professor Gosden said attempts had begun to repeat the experiment using sheep, which have a more similar reproductive system to humans.

"If it works in a larger species, and we'll have to wait and see, I'm really quite optimistic that people will move on to trying this in patients maybe in two or three years' time," he said.

"All the gynaecology surgeons I've spoken to say it should be straightforward to do an ovarian transplant. There won't be problems with surgery." The technique relies on a new method of freezing the whole organ in such a way that the delicate tissues and cells are not destroyed after being frozen at temperature of about minus 200C.

In addition to storing the whole ovaries of young women being given chemotherapy or radiation treatment, Professor Gosden said that it might be possible to use the technique to help to reduce the risk of premature sterility for other medical conditions.

He said: "There is the possibility of protecting fertile potential for women who have a genetic risk of early menopause before the age of 40.

"There is good evidence that quite a lot of those cases are genetic, where people have had a mother or sister with early menopause and where the risks are much higher."

If ovary banking worked for cancer patients and was deemed safe, then healthy women who wanted to store one of their ovaries for later in life could also benefit, he said.

"If the technology got to that point of efficiency and safety, you could imagine that happening ... I think it's possible, it will depend on the technology but there are certainly people who would consider it if the risks are absolutely minimal," Professor Gosden said.

"It's certainly not on our agenda now but I would imagine certainly people are interested in that."