Twin ovary transplant successes

The Yarber sisters were the first to undergo the transplant

Scientists have successfully carried out a series of ovarian transplants on women with an early menopause by using tissue from identical twin sisters.

The US team hit the headlines last year when Stephanie Yarber, who went through the menopause at 14, had a baby after her twin sister donated tissue.

Another five women have now had the operation, three of whom are pregnant.

A study in Human Reproduction shows twins have a three to five times higher rate of premature ovarian failure.

Dr Sherman Silber from St Luke's Hospital in St Louis and Dr Roger Gosden, professor of reproductive biology at Cornell University in New York began to investigate premature ovarian failure after noticing that some twins had very different menopausal ages.

It's quite a high level of success and it seems encouraging Dr Allan Pacey

By looking at data from 832 twin pairs in Australia and England they found that, at 40 and 45, identical and non-identical twins had a three to five-fold increased risk of an early menopause than other women.

The findings are published in the journal Human Reproduction, but the researchers also presented data on the successful transplants to delegates at the American Society of Reproductive Medicine conference in New Orleans.

Dr Silber is planning operations on a further five women.

The operation involves removing the outer tissue that contains the egg-producing follicles from the healthy twin's ovary and grafting it back onto the ovary of the infertile twin.

The risk of organ rejection is minimal because identical twins have the same genes increasing the chances of success.

Experts said the work would help us to better understand how to help women who want to preserve their fertility prior to potentially sterilising cancer treatment.

Prevalence

Dr Gosden said it was unclear exactly why twins had a higher risk of premature ovarian failure compared to other women, particularly identical twins.

"The phenomenon, although still rare, is much more common than we imagined. It's more of a mystery in identical twins because you would expect them to be very similar. We think that whatever is causing it is happening very early on before birth."

He added that mothers of non-identical twins may have a tendency to early menopause, which the twins are inherited.

"In mothers whose biological clock is running faster than normal, the likelihood of having twins switches to an earlier age - to their peak childbearing years," he said.

Dr Allan Pacey, secretary of the British Fertility Society and senior lecturer at Sheffield University, was impressed by the success rate of the ovarian transplants.

"It proves the technology works. This is interesting because it will allow us to develop technology that will help young women have bits of their ovaries removed before cancer treatment. It's quite a high level of success and it seems encouraging."

He added that more work would be needed to work out how to preserve ovarian tissue for a long time in women having tissue removed to protect fertility.