Breakthrough for cancer victims hoping to give birth

A woman has given birth to the first baby to be conceived after an undeveloped human egg had been "ripened" in the laboratory and frozen before being fertilised by IVF.

The procedure - a world first - marks an important development in the ability to offer young women with cancer the capacity to retain their fertility after a bout of sterilising chemotherapy.

The unnamed woman lives in Canada and her baby girl is doing well, according to Hananel Holzer of McGill University's Reproductive Centre in Montreal. Three other women are pregnant following the same procedure, he said. Until recently it has proved difficult to stimulate the development of immature human eggs in the test tube and freeze them until such a time when the woman requests to get pregnant with IVF treatment.

But Dr Holzer and his team have managed to do both and opened the way for women with cancer or diseases such as polycystic ovarian syndrome to become pregnant later in life when they are ready or healthy enough to start a family.

Dr Holzer took immature human eggs from 20 women with polycystic ovarian syndrome and matured them in the test tube by bathing them in a cocktail of nutrients devised by the scientists.

The laboratory development of the immature eggs meant that the women did not need to undergo hormonal stimulation, which artificially matures eggs in the ovary but carries its own health risk, especially for women with polycystic ovarian syndrome.

"Unfortunately, some patients seeking fertility preservation may not have enough time for ovarian stimulation, or have a medical condition deemed by some oncologists as a relative contraindication to hormonal stimulation, such as oestrogen-receptor-positive breast cancer," Dr Holzer said.

In such circumstances, human eggs could be collected from the ovaries without hormonal stimulation and matured in the laboratory before being frozen until the woman was ready to carry a baby following IVF treatment."We have demonstrated for the first time that it is possible to do this and, so far, we have achieved four successful pregnancies, one of which has resulted in a live birth. The other three pregnancies are ongoing," Dr Holzer said.

"These results are preliminary and the pregnancy rate is probably associated with a learning curve. Indeed, three of the pregnancies were achieved in the last five patients," he told the European Society for Human Reproduction and Embryology in Lyon.

"Our research shows it is possible to collect immature oocytes [egg cells] from unstimulated ovaries, mature them in vitro, freeze and thaw them and then achieve pregnancies and live births, without the risk of aggravating the patients' hormone-sensitive disease, delaying treatment for cancer or re-instituting a metastatic malignant disease," he said.

Treating cancer patients with the technique has not yet been attempted but it potentially offers a safer route to motherhood than transplanting ovarian tissue back into the woman, which runs the risk of re-introducing cancerous cells, Dr Holzer said. But he cautioned: "We have to remember these are only preliminary results from a small number of patients who were not cancer patients."