A treatment to grow the cells that provide a woman's life-time stock of immature eggs in a laboratory could revolutionise fertility preservation, it has been claimed.
The British breakthrough, which is still being studied, found early stage follicles can be grown and matured in artificial conditions.
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 anticancer drugs can destroy follicles in the ovaries, wiping out any possibility of a woman having children.
Primordial follicles are the tiny egg-bearing 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.
A team led by Dr Evelyn Telfer, from the University of Edinburgh, succeeded in growing primordial follicles to a late stage of maturation in the laboratory.
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."