06 June 2011
ByAppeared in BioNews 610
British scientists have grown mature eggs from undeveloped ones in the laboratory and are currently seeking permission to fertilise them. The new research gives hope to young girls undergoing treatment for cancer that may leave them infertile.
Adult women undergoing chemotherapy are offered egg freezing in case they are left infertile by the treatment. But this is not possible for children because their eggs are undeveloped.
In this new research, scientists at the University of Edinburgh took tissue containing undeveloped eggs from the ovaries of adult women and grew them to maturity.
Dr Evelyn Telfer and Professor Richard Anderson, who carried out the work, have applied to the Human Fertilisation and Embryology Authority (HFEA) for a licence to fertilise these eggs. While legal and ethical permission is being considered, the researchers are assessing the health of the eggs.
The researchers also took tissue samples from the ovaries of girls as young as eight before they had chemotherapy, but they felt it was inappropriate to use these for experiments.
Dr Telfer told the Sunday Times: 'These girls are offered the opportunity to have a small piece of their own ovary removed and stored. The technique we are working on is to activate [undeveloped eggs] in vitro and to grow the eggs completely outside the body and eventually to be able to fertilise them and produce embryos from that tissue. We are getting almost fully developed eggs now'.
A group of Israeli doctors in 2007 claimed to have extracted and matured eggs from girls as young as five for freezing for future use. It has since been reported that the doctors managed to find some eggs in the young girls that had already started maturing which, according to the British researchers, is rare in pre-adolescence.
They argue that a more abundant supply of immature eggs is found in ovarian tissue and, if the technique is successful, may provide a more reliable treatment. Professor Anderson said that 'if you take a piece of ovarian tissue and start from that then you could potentially have hundreds of eggs or more'.
Around 1500 children under 15 are diagnosed with cancer each year in the UK.