Scientists have for the first time managed to grow human eggs outside of the womb.
The researchers removed young eggs from a woman and grew them in a lab to the point where they were ready to be fertilised.
They believe the development could offer new hope to some women who struggle to conceive, including cancer sufferers.
"Being able to fully develop human eggs in the lab could widen the scope of available fertility treatments," said lead researcher Professor Evelyn Telfer, of the University of Edinburgh's school of biological sciences.
There has been a cautious welcome for the news from one of Ireland's leading fertility experts.
Professor Simon Fishel, from Beacon CARE Fertility, has said that further research is needed to establish whether eggs grown this way would be healthy and viable.
"This study demonstrates that there is much laboratory research to be undertaken before we can be encouraged to believe that we will achieve healthy normal eggs for clinical purposes in vitro developed follicles derived from human ovarian cortical tissue," he said today.
The researchers took egg cells at the earliest stage of development from ovary tissue in a woman and grew them to peak maturity outside her body, a first in human beings.
Similar research was previously conducted in mice.
The study was carried out by the Royal Infirmary Edinburgh, the Centre for Human Reproduction in New York and the Royal Hospital for Sick Children in Edinburgh.
