Embryo test boosts IVF pregnancy rates

Ailsa Taylor

Progress Educational Trust

11 July 2008

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[BioNews, London]

A new test which helps IVF doctors pick the healthiest embryos for transfer may boost pregnancy rates by up to 15 per cent, was unveiled at a European fertility conference this week. The test, which takes just one minute to carry out and will be used alongside standard IVF methods for embryo selection, is due to start trials later this year and may be available in UK clinics early next year.

'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,' lead researcher Denny Sakkas, professor at Yale University school of medicine, told delegates at the European Society for Human Reproduction and Embryology annual meeting.

Conventional IVF relies on choosing embryos for transfer by examining their size and shape under a microscope. But the researchers found that this method was only accurate at identifying viable embryos - those which would result in a pregnancy - 40 per cent of the time. Their technique - known as 'ViaTest-E ' - involves shining a light through the fluid surrounding the embryo in order to measure it's metabolic activity - rather like the technique used to tell whether milk is full or half-fat.

Testing the ViaTest-E device on 500 embryos showed accuracy rates of 60-70 per cent, potentially boosting the chance of pregnancy for women under 35 in the UK from 30 percent to 45 per cent. It is anticipated that tests which help doctors select the most viable embryos will be vital in order to support the move towards single embryo transfer, a measure being implemented across Europe and the rest of the world to try and limit multiple births.

Dr Daniel Brison, co-director of the North West Embryonic Stem Cell Centre in Manchester, told the BBC that improvements to IVF success rates were urgently needed. 'If we can get better at choosing the best embryo to implant then we can increase the efficiency of IVF, move towards single embryo transfers and thus reduce the risk to mothers and babies,' he said.

Reproduced with permission from BioNews, an email and online sources of news, information and comment on assisted reproduction and genetics.