A NEW test which could boost IVF success rates by up to 80 per cent has been hailed by experts at a major international conference.
Scientists at Oxford University have discovered that high levels of energy-producing cells in the embryo, known as mitochondria, prevent the embryo from implanting and producing a baby.
Fertility expert Professor Dagan Wells, one of the authors of the study published in the journal PLOS genetics, said the test could help couples undertaking fertility treatment, as the majority of embryos created through IVF “have no chance at all” of resulting in a successful pregnancy.
Prof Wells said: “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.”
Only a third of IVF transfers in the UK are successful.
The clinical trial carried out by the Oxford group and Reprogenetics, a specialist fertility group, used embryos grown in the laboratory until they are five days old.
At this time, embryos are made up of around 100 cells, of which five are removed for testing.
Scientists already know that more than half of all embryos are chromosomally abnormal and will not result in a baby. Even of those embryos that are chromosomally normal, a third will still not implant.
The new tests involves usual chromosomal screening then looking closely at why the remaining embryos are still not resulting in a baby.
Prof Wells said: “A significant number of embryos have unusually high levels of mitochondrial DNA and have too much of it.
“Having mtDNA above a certain threshold seems incompatible with implantation of an embryo.”
Prof Wells said it is still unclear why the embryos produce too much mtDNA. New work will try to find out why this is.
He said he hoped that at some point in the future, chromosomal testing plus the new mtDNA test would be available on the NHS rather than just through private IVF clinics.
Stuart Lavery, consultant gynaecologist at Imperial College London, said: “This new finding of mitochondrial assessment could offer an additional opportunity to screen embryos prior to implantation, helping patients get pregnant quicker.”