Cancer & Infertility

The first human embryo to be created after an ovarian transplant may signal hope for women.

The first human embryo to be created after an ovarian tissue transplant may signal hope for hundreds of thousands of women made infertile by cancer treatment.

Researchers have been attempting to transplant ovarian tissue in humans for many years but this is the first time that they have obtained good quality eggs from a transplant and a viable embryo.

Kutluk Oktay, at Cornell University in New York, and colleagues took a strip of ovarian tissue from a 30-year-old woman with breast cancer before chemotherapy made her infertile. They froze the tissue and six years later transplanted it beneath the skin of her abdomen.

After three months, the tissue started functioning normally and produced eggs. Those that were viable were fertilised in the test tube, resulting in one promising embryo.

"This research represents a potentially significant reproductive advancement in two respects: first, women can preserve their fertility by freezing their ovarian tissue, and second, pregnancy may be possible even after the tissue remains frozen for a long time," said Oktay.

Oktay told 'New Scientist' that the method might also help children with cancer, offering hope to girls who are too young to have In-Vitro Fertilisation (IVF) before undergoing cancer treatment.

Oktay and colleagues have transplanted human ovarian tissue before, but the primordial follicles that contain the undeveloped egg had been at a very early stage. This means that the eggs harvested had not been sufficiently developed for IVF.

However, improvements to the way in which the eggs are harvested enabled the team to obtain 20 eggs in their latest attempt, eight of which were suitable for IVF.

Smitz, however, cautions that transplanting ovarian tissue could also pose risks. "We have to be very careful that by replacing this tissue back into the body of cured cancer patients, we also don't reintroduce cancer cells," said Smitz.