IVF test could more than double success rate to over 80 per cent

Experts have discovered that the levels of a particular type of DNA in a developing embryo are a crucial factor in whether a pregnancy will be successful and a simple test can be used to select the most viable embryos.

The development has the potential to revolutionise the success rate of fertility treatment, which currently stands at about 35 per cent of IVF cycles resulting in a pregnancy. Some 50,000 women undergo IVF treatment in Britain every year.

Clinical trials conducted in New York using the new technique, which was developed by researchers at Oxford University, resulted in a pregnancy success rate of around 80 per cent.

Professor Dagan Wells, the Oxford specialist who led the research team, told the Press Association that the test could be hugely beneficial for would-be parents who often face multiple disappointments and considerable expense going through repeated IVF treatment cycles.

The new technique focuses on mitochondria, the part of the cell that is its main energy provider and plays a key role during the development of an embryo.

The Oxford researchers, who have been shortlisted for two prizes in the field of fertility research as a result of their work, found that some embryos have excessive levels of mitochondrial DNA – or mtDNA – and will consequently not produce a viable pregnancy.

Prof Wells said those undergoing IVF treatment already faced an uphill struggle because the majority of embryos created in the process of harvesting eggs and artificially fertilising them with sperm have “no chance at all” of becoming a baby.

The success rate for IVF is rising by about one per cent a year but Prof Wells said that progress was “painfully slow” and woman who, for example, produces eight embryos may have only one that will result in pregnancy.

He said: “You are potentially putting your patient through eight embryo transfers before you get to the one embryo that is viable. For the patient repeatedly having negative pregnancy tests, that’s brutal.

“Any test of the embryo that will result in a baby is therefore highly desirable.”