Ten out of 32 women who wanted to become pregnant and had transplant succeeded in having a baby, and none had cancer recurrence as a result. Ovarian tissue transplants for women who want to have a baby after cancer treatment appear to be safe and are very successful, according to a team of experts in Denmark, where the procedure is routinely offered.

One in three young women who had a transplant and wanted to become pregnant succeeded in having a baby, analysis of results over the last 10 years has shown. Half of the children were conceived naturally, without the help of IVF.

The study, published in the journal Human Reproduction, is likely to be a game-changer. Many doctors have been wary of ovarian tissue transplants, worried that they might cause a return of the cancer. But among the 41 women in the study, none had a recurrence as a result.

The successes also bring closer the potential option for women to postpone having a family by having ovarian tissue frozen until they are established in a relationship or career, without having to worry about the ticking of the reproductive clock.

In Denmark, young women with cancer are routinely offered ovarian tissue freezing, but it is not automatic in the UK or elsewhere.

“We are saying for the first time we have a cohort of patients who definitely seem to benefit from this and none of those women have had a cancer as a result of transplanting the tissue,” said one of the study’s authors, Prof Claus Yding Andersen, of the Laboratory of Reproductive Biology in the Rigshospitalet, Copenhagen.

“Most surprising to me is that we have patients who have tissue that is active more than 10 years after the transplant.” Some of the women asked for the transplant because they hoped to start a family, but others did it to reverse the early menopause their treatment had triggered. “We have women who say ‘I don’t have a partner at the moment but I don’t want this menopause’,” said Andersen.

“Of course, if you have a cancer as a young woman, all of them say ‘I would like to survive’, but immediately after that most of them say ‘is it possible to preserve my fertility’. It is a huge issue for the patients.”

If the procedure can be shown to be safe and effective, it opens the way to young women having ovarian tissue removed and frozen so that they can postpone having children until the time seems right for them, whether because they have established themselves in a career or found the right partner.

“This is a theoretical adaptation,” said Andersen. “I think it is a bit early to take it that far but in a few years, when we know even better what we are doing, it may become an option.”

Denmark leads the world in ovarian transplantation. “I’m always asked how can it be that a small country with five million people is having the largest experience with this worldwide,” said Andersen. “Here we have a public healthcare system and women are offered the procedure for free. We take out the ovary and cryopreserve it for free and transplant it for free.

“Colleagues in the UK have been sceptical about the safety and longevity of the tissue. They were asking are you sure you are doing no harm? But there are lots of clinics in London starting to offer it now.”

At least 36 babies have been born following the procedure, mostly in Denmark. Germany, Spain, Israel and Belgium have also done significant numbers of transplants. “The results are very encouraging for a continued effort,” Andersen said.

The study is a review of the largest series of ovarian transplants performed worldwide. The experts looked at the outcomes for 41 women, who had 53 transplants of thawed ovarian tissue between them over a period of 10 years. Among the women, 32 wanted to become pregnant and 10 succeeded in having babies – a total of 14 children in all. Some others became pregnant but there was one miscarriage and two abortions, one because a relationship broke down and the other because the woman’s cancer returned, unconnected with the transplant.

The Danish procedure involves removal and cryopreservation of one ovary. During transplantation, part of that ovary is cut into 25 small pieces and inserted into the remaining ovary, which then regains its function. The hormonal cycle resumes and an egg is produced each month. Half the children born were conceived naturally. The tissue can be transplanted elsewhere in the abdominal cavity if necessary, which means IVF will be required.

Grete Brauten-Smith, clinical nurse specialist at Breast Cancer Care, said young women facing cancer treatment must be offered advice on their options from a fertility specialist.

“Chemotherapy treatment can cause infertility – a massive worry for thousands of younger women with breast cancer. So it is very encouraging to see these improving success rates for freezing ovarian tissue,” she said. “This could, in future, offer another valuable option for those who face the devastating prospect of not being able to start or add to their family.

“It is vital women are offered a referral to a fertility expert before starting treatment. Only then will they be able to make an empowered decision about their future fertility.”

Sarah Boseley, Health editor

The Guardian http://www.theguardian.com/society/2015/oct/07/ovarian-tissue-transplants-safe-successful-study