Writing in the journal Molecular Human Reproduction, researchers from Edinburgh and NY describe how they took ovarian tissue from 10 women in their late twenties and thirties and, over four steps involving different cocktails of nutrients, encouraged the eggs to develop from their earliest form to maturity.
Scientists have previously developed mouse eggs to produce live offspring and matured human eggs from a late stage of development.
While the breakthrough is huge news for people who might be struggling to start a family, experts in the field have called for caution.
"If we can show these eggs are normal and can form embryos then there are many applications for future treatments", says University of Edinburgh Professor Evelyn Telfer. In addition to helping cancer patients preserve their fertility, he said it could deepen scientific understanding of the biology of the earliest stages of human life. They took samples of ovarian tissue from 10 women while they were undergoing caesarean section surgery and cultured sections of that tissue that have the ability to release an egg, structures known as follicles.
However, putting the tissue back carries a risk of reintroducing cancer. This discovery is considered a big breakthrough for the future of fertility preservation.
The authors of the study explain that most females are born with undeveloped eggs within their ovaries. The eggs have not also been fertilized, so researchers are still uncertain how viable these are.
'We also hope to find out, subject to regulatory approval, whether they can be fertilised'.
'It could be an alternative to conventional IVF'.
Kent University's Darren Griffin, a genetics professor who did not work on the project, told Reuters it's "an impressive technical achievement".
The study, carried out in collaboration with the Royal Infirmary Edinburgh, The Center for Human Reproduction in NY and the Royal Hospital for Sick Children in Edinburgh, was supported by the Medical Research Council. They accomplished this feat; however, the eggs have yet to be fertilized.
The first mouse created using lab-produced eggs was born in the United States in 1996.