A two-year-old girl has become the youngest patient to benefit from a new technique to preserve the fertility of young cancer patients, scientists have said.
The therapy - carried out in the UK - was part of a study involving 5 young girls aged two to 17, and eight women aged 22 to 31, who took part in the research between 2013 and 2015.
What did it involve?
Scientists at Oxford Fertility and Oxford University successfully managed to extract ovarian tissue and immature eggs from young girls.
The eggs were then matured in the labortary using an established technique known as in vitro maturation (IVM).
Once matured the eggs and tissue were quickly frozen for a future date.
The ovarian tissue was frozen with the view it could potentially be transplanted back into the female participants in the hope their bodies will start producing their own eggs.
What does this mean for the future?
The procedure was carried out with a view to potentially transplanting the ovarian tissue back into the female participants in the hope their bodies will start producing their own eggs.
Experts have been advancing and perfecting techniques to preserve fertility in all age groups and around 50 babies have been born worldwide following successful ovarian tissue freezing.
But to date there are very few options for younger girls who have not yet gone through puberty.
IVM has the advantage of avoiding the risk that potentially cancerous cells are reintroduced to a woman at a later date.
Scientists believe it could pave the way for very young cancer patients to effectively put their "fertility on ice" while they undergo intensive treatments, which could potentially leave them infertile.
What do scientists say?
Professor Tim Child, from the University of Oxford and medical director of Oxford Fertility, said they had taken a "belt-and-braces approach" to looking at fertility preservation in adolescent or pre-pubertal girls.
Prof Child said the two-year-old girl, who cannot be named, was "definitely the youngest" to have eggs frozen using IVM.
He also said that it was not yet known whether the technique would be more successful than merely freezing tissue, but his team "have good reason" to think it would work.
"It's two bites of the cherry - we freeze the tissue and freeze the matured eggs," he added.
The findings were presented at the European Society of Human Reproduction and Embryology conference in Helsinki.