Infertile woman gives birth in Japan after ovarian tissue implants

A 30-year-old infertile woman gave birth after surgeons removed her ovaries and reimplanted tissue they treated in a lab, researchers report.

The new mother gave birth to a son in Tokyo last December, and she and the child continue to be healthy, said Dr Kazuhiro Kawamura of the St Marianna University School of Medicine in Kawasaki, Japan. He and others describe the technique in a report published online on Monday by the Proceedings of the National Academy of Sciences.

The mother, who was not identified, had been diagnosed with primary ovarian insufficiency, an uncommon form of infertility sometimes called premature menopause. It appears in about 1 per cent of women of child-bearing age. The cause of most cases is unknown, but the outcome is that the ovary has trouble producing eggs.

That leaves women with only a 5 per cent to 10 per cent chance of having a baby unless they get treated. The standard treatment is using donor eggs.

Kawamura and colleagues were able to recover eggs from five of their 27 patients. One woman had a miscarriage, one did not get pregnant and two more have not yet attempted pregnancy, Kawamura said.

In the ovary, eggs mature in structures called follicles. For women with the condition the new study targeted, the follicles are either missing or failing to produce eggs. The experimental treatment was designed to stimulate dormant follicles.

First, the women's ovaries were removed and cut into strips, which were frozen. Later the strips were thawed and cut into tiny cubes, a step intended to stimulate maturation of the follicles. Then the cubes were treated with drugs to stimulate further development of the follicles. Cubes were then transplanted just under the surface of the women's fallopian tubes.

Within six months, eight women showed signs of follicle maturation, and five of them produced eggs for fertilisation in the lab with their husbands' sperm. The fertilised eggs were grown into early embryos, which were frozen for preservation. In the three attempts at pregnancy, one or two embryos were implanted in the women.

The researchers found half the 27 patients had no follicles at all, which meant the treatment could not help them, said Aaron Hsueh of Stanford University, senior author of the study. He also said researchers hope to find a way to stimulate follicles without removing the ovaries.

Dr Sherman Silber of the Infertility Centre of St Louis criticised the approach, saying he has had success by using drugs rather than surgery to treat the condition. He also disagreed with the explanation for why the treatment worked. Some other experts said treatment with drugs often does not work.

The new results, experts cautioned, must be viewed as preliminary.

"It shows a lot of promise [but] I don't think it's even close to being ready" for routine use, said Dr Mark Sauer of the Columbia University Medical Centre in New York.

The reported efficiency is very low, and the possible health risk to babies born from the method is unknown, said David Albertini of the University of Kansas Medical Centre.