Egg breakthrough could preserve fertility

Published on Sunday 20 April 2008 22:00

SCIENTISTS in Scotland yesterday revealed a major breakthrough in helping to preserve women's fertility.

A team from Edinburgh University have succeeded in taking early stage follicles from a woman's ovaries and maturing them into eggs in the lab for the first time.

The discovery should help women undergoing cancer treatment, or those wishing to delay motherhood so they can concentrate on their careers. It could revolutionise the preservation of fertility for women in the next five to ten years.

The team, led by Dr Evelyn Telfer, was able to develop early stage follicles – tiny egg-bearing pockets in the ovaries – to a much later stage.

They took pieces of ovary containing the follicles from six volunteer women who were giving birth by elective caesarean section. These were then exposed to an artificial growth factor. Around a third of the follicles survived and went on to reach an advanced stage.

Dr Telfer said: "This is a significant step in developing immature eggs to maturity outside the body. Women who face infertility as a result of chemotherapy, or who want to put their biological clock on hold, could benefit from this system.

"However, there is a lot more research to be carried out before this technique could be safely applied within a clinical setting," she added.

At present, women undergoing cancer treatment can have a piece of ovary removed and frozen for future transplantation. But this carries the risk of reintroducing cancer cells to the patient. They can also take fertility drugs to produce eggs to be harvested for use at a later date. But this poses risks in delaying treatment, and defrosting the eggs does not always work.

Maturing eggs in the laboratory would allow them to be screened for cancer before they are returned and also taken as soon as a diagnosis is made, according to the research published in the journal Human Reproduction.

Women who want to preserve their fertility past the menopause could also have their follicles stored for later use when they are ready to start a family.

As yet the scientists do not know whether eggs matured in this way are completely normal and suitable for in vitro fertilisation. However, animal studies suggest that they are.

"We believe there's good evidence that we can get normal oocytes (eggs], but of course you would never apply this technique clinically until you are sure," said Dr Telfer.

Dr Jane Stewart, a consultant in reproductive medicine at the Newcastle Fertility Centre, said the research took scientists a step nearer to the goal of storing immature eggs for fertility preservation for women.