Fitness test for embryos

Fertility doctors have developed a fitness test for embryos which they claim could substantially improve the chances of pregnancy. The one-minute test is to be carried out alongside standard IVF treatment and could be approved for use in fertility clinics from late next year.

Trials of the test, which helps doctors select the healthiest embryos, showed that the method boosts the chances of embryos implanting.

Doctors who developed the technique say it could improve pregnancy rates by 10% to 15%.

Large-scale trials at hospitals in Amsterdam and Gothenburg will begin in October.

In British fertility clinics the overall average pregnancy rate is 21,6% per cycle of treatment, though this rises to 29,6% for women younger than 35.

Speaking at the conference of the European Society of Human Reproduction and Embryology in Barcelona on Tuesday, Denny Sakkas, professor at Yale University school of medicine, said: “We fail to get patients pregnant about two-thirds of the time we transfer an embryo, and one of the reasons is we are not very good at picking the best ones from those available.”

In IVF treatment eggs collected from a woman are fertilised and grown in a culture medium. Typically about eight embryos grow each time. Traditionally doctors decide which are the best embryos by looking through a microscope to see how well they are growing, a process some claim is more of an art than science.

In the new “fitness” test, which measures embryo metabolism, doctors remove fluid from the embryo’s culture medium and shine infrared light through it. This produces a biological “fingerprint” which reveals levels of compounds, such as glucose, in the growth medium, which have been either used by the embryo or excreted.

Sakkas’s team tested the culture media of more than 1 000 embryos after they had been implanted in women. They found that those with the highest fitness scores were far more likely to have brought about pregnancy, with implantation rates rising from 26% to 39%.

Sakkas said the method took the accuracy in picking suitable embryos from 40% to up to 70%.

The equipment for the tests costs about £10 000, although the cost for a single test is expected to be considerably cheaper.

Daniel Brison, at the IVF unit in Manchester, said the test could help fertility clinics meet the British regulator’s targets for cutting numbers of twin IVF births.—