A two-year-old girl has become the youngest person to undergo a new technique that could preserve her fertility after chemotherapy.
By freezing these tissues before they are exposed to the potentially fertility-reducing effects of chemotherapy, the technique could allow even very young cancer patients the possibility of having genetically related children later in life.
Professor Timothy Child, from the University of Oxford and medical director of Oxford Fertility, where the pilot is taking place, said: 'If we're looking at fertility preservation in adolescent or pre-pubertal girls, then, around the world in general, not a lot can be done for them. In Oxford, we have taken a belt-and-braces approach.'
The procedure involves a laparoscopy to remove some ovarian tissue, which is then frozen and can be transplanted in later life to assist with fertility. The researchers went further, however, and were also able to extract immature eggs from the follicles, which were matured in vitro and then frozen. 'It's two bites of the cherry,' said Professor Child. 'We freeze the tissue and freeze the matured eggs.'
So far, around 50 babies have been born worldwide following ovarian tissue freezing, mostly from adults or older children. There has been some doubt over whether the procedure would work with pre-pubescent girls, but earlier this year a 23-year-old woman received a transplant of ovarian tissue frozen when she was eight years old (see BioNews 844). At two years old, one of the patients involved in this study is thought to be the youngest person from whom such tissue has been frozen.
Being able to isolate immature eggs may also offer advantages over just freezing ovarian tissue. Speaking in The Telegraph, Mr Stuart Lavery, consultant gynaecologist at Hammersmith Hospital and who was not involved in the study, said: 'In the future the idea is to put those little pieces of ovary back into the person themselves but the worry has always been could there be some cancer cells.
'What this study shows is that they were able to actually grow and isolate some eggs from that tissue – so the idea is could you use those eggs in future without having to transplant the ovary back.'
The findings were presented at the European Society of Human Reproduction and Embryology annual conference held in Helsinki.