Embryo test could increase IVF success rate

A new test to identify embryos most likely to result in a pregnancy could double the success rate of IVF US researchers claim. Researchers at the Sher Institutes for Reproductive Medicine say the new test, which samples the embryo growth fluid, could cut the number of embryos used in fertility treatments. The team published their findings in the Journal of Reproductive Biomedicine.

The test works by detecting a chemical called sHLA-G, which is thought to help embryos survive after implantation in the womb. During IVF, embryos release sHLA-G into the fluid in which they are grown in the lab. Geoffrey Sher and his colleagues looked at fluid samples from nearly 600 embryos to find out if the level of sHLA-G was linked to the outcome of the pregnancy.

The researchers found that 71 per cent of women aged under 39 who had above average levels of sHLA-G became pregnant, compared with just 22 per cent of those who had below average levels of the chemical. Women over 39 were less likely overall to become pregnant, but those with a higher sHLA-G level were most likely to have successful IVF treatment. Based on these results, Sher says he is already screening the embryos of all women attending his US clinics, to choose the best embryos for implantation. He says the procedure 'brings IVF practitioners much closer to the long-awaited objective of 'one embryo, one healthy baby''.

However, other fertility experts have warned that further work is needed before the test is used routinely in IVF treatment. Currently, doctors select embryos on the basis of appearance, unless they are being tested for a particular genetic disease. A spokeswoman for the UK's Human Fertilisation and Embryology Authority welcomed the new research, as it could reduce the number of multiple IVF births: 'Any technique, having gone through appropriate clinical trials, which is shown to increase a woman's chance of becoming pregnant, could mean a move towards single embryo transfer. This would be good for mother and baby'.