Researchers at Oxford University have developed a test that may help to improve IVF success rates by checking the health of embryos.

The team, led by Dr Dagan Wells, has apparently developed a test which checks embryos during IVF for abnormal numbers of chromosomes. They tested a few cells taken from early human embryos, each of which should contain 23 pairs of chromosomes. With more or less than this, embryos can fail to develop normally.

They then looked at other properties of the cells which had abnormal chromosome numbers. They saw changes in the lengths of telomeres, regions of DNA at the ends of chromosomes, and in the number of mitochondria, structures which provide a cell with energy.

The scientists suggest that the length of telomeres and number of mitochondria could be new indicators that could help to select healthy embryos during IVF. The hope would be that these embryos are more likely to implant successfully and survive to term.

'I think it offers the possibility of enhancing success rates of IVF, allowing couples to get to the point of having a baby more rapidly with fewer cycles, and avoiding the heartbreak of miscarriage or terminating a pregnancy because of serious disorders', said Dr Wells.

The research was announced at the American Society for Reproductive Medicine's annual conference this week and is currently unpublished. More still needs to be done to ensure that it is an effective method of predicting embryo viability, and it would have to go through clinical trials before it could be used in patients.

The chairman of the British Fertility Society, Anthony Rutherford, said of the research: 'This exciting novel technique is taking the molecular assessment of the embryo to a new level and clearly is an important tool for research into embryo health. […] The difficulty we face is making sure adequate funding is made available to allow this new technique to be assessed fully before it enters clinical practice'.