One of the most important factors influencing the success of IVF treatment is the health of the embryo selected for transfer to the womb.
Approximately 85 per cent of all embryos transferred do not ultimately go on to produce a baby. In recent years the importance of counting chromosomes in the cells of embryos was discovered.
Yet even when embryos with the correct number of chromosomes are transferred, about one-third still fail to implant for reasons yet unknown.
However research teams at Reprogenetics and the University of Oxford have now discovered a new factor that influences the success of IVF – the level of an embryo’s Mitochondrial DNA.
Between a quarter and a third of embryos have abnormal levels of mitochondrial DNA which means they will never implant.
Microscopic bodies, hundreds or thousands of Mitochondria can be found within each of our cells. They are responsible for producing the energy needed by cells, essential for life. Each mitochondrion contains a small quantity of DNA.
Dr Elpida Fragouli, who led the research at Reprogenetics, said: “Based on our findings we have devised a test whereby a small number of cells, carefully removed from an embryo, can be measured for the amount of mitochondrial DNA present. This will help guide doctors to the IVF embryos with the greatest chance of producing a viable pregnancy.”
Prof Dagan Wells, who is funded by the NIHR Oxford Biomedical Research Centre, said: “Currently, only about one IVF treatment in every three succeeds in helping a couple to have a baby.
“Anything that reduces the number of unsuccessful embryo transfers that patients have to endure will certainly be welcome. This important discovery indicates that mitochondria represent an important piece in the complex jigsaw puzzle that is infertility.”
The research also revealed that the levels of mitochondrial DNA in embryos tend to increase as women age, implicating mitochondria with reproductive ageing.
Trials of the new technology for mitochondrial DNA assessment, which has been christened MitoGrade, are already underway in the United States, while Reprogenetics is in the processes of applying to the British IVF regulator, the Human Fertilisation and Embryology Authority (HFEA), for permission to offer this test in the UK.
Initial data from 100 American patients suggests that the chance of choosing a viable embryo for transfer is likely to be boosted by 10 per cent if MitoGrade results are taken into consideration.