Breakthrough may revolutionise fertility treatment.

EARLY stage follicles which provide a woman's life-time stock of immature eggs can be grown and matured in the laboratory, scientists have shown for the first time.

The British breakthrough, which is still being studied, has the potential to revolutionise fertility preservation for women in the next five to 10 years.

A key application would be safeguarding the fertility of women about to undergo chemotherapy for cancer, whose follicles could be removed before the start of treatment.

Powerful anti-cancer drugs can destroy follicles in the ovaries, wiping out any possibility of a woman having children.

Another possibility is that the technique could help women wanting to side-step the menopause, or delay motherhood for the sake of their careers. It could also provide a potentially rich source of eggs for scientists, including those studying stem cells.

Last summer, Canadian scientists from the McGill Reproductive Centre, in Montreal, announced the first birth of a child created from a human egg matured in the laboratory.

But the eggs they used, though immature, were a far cry from the primordial follicles studied by the British researchers.

These are the tiny eggbearing pockets within the ovary that are present in their millions at birth but gradually die off over the course of a woman's life. They represent a woman's fertility "battery" which, once depleted, cannot be recharged.

Many follicles remain dormant, but some go on to mature and eventually release their eggs in preparation for fertilisation.