A breakthrough in fertility science could lead to a huge boost in the success of IVF, scientists said today.

IVF - or ‘in vitro fertilisation’ - is currently the only hope for many women to have a baby, and some 50,000 undergo the treatment every year in Britain.

But despite its popularity, the procedure has a poor success rate, with 75 per cent of IVF rounds failing to produce a baby.

Scroll down for video

Despite its popularity, IVF (pictured) has a poor success rate, with 75 per cent of rounds failing to work

Manchester University researchers now think they have found a way to slash the failure rate by half.

They have discovered a ‘molecular switch’ which stops an embryo being accepted in the mother’s womb.

If that switch can be blocked with drugs, it could potentially boost the number of babies born using IVF by up to 18,000 a year.

About 37 per cent of IVF rounds are thought to fail because the embryo does not implant into the wall of the uterus.

Women who repeatedly suffer this failure have been shown to have high levels of a molecular switch which interferes in the communication between the embryo and the mother’s womb.

In laboratory tests, the researchers found that if they reduced levels of the molecule - called microRNA-145 - the embryo was less likely to be rejected.

Study leader Professor John Aplin, whose work is published in the Journal of Cell Science, said: ‘When an embryo is ready for implantation, its replacement is carefully timed to coincide with the window of maximal receptivity in the uterus.

‘This window is open for no more than four days.’

Professor Aplin’s team found that a protein called IGF1R is required during the four-day window for the embryo to stick to the uterus.

Their tests suggest that the microRNA-145 molecular switch stops the crucial protein from growing in that window.

Scientists have discovered a ‘molecular switch’ which stops an embryo being accepted in the mother’s womb. If that switch can be blocked with drugs, it could potentially boost the number of babies born using IVF by up to 18,000 a year

Dr Karen Forbes, a reproductive scientists who worked on the project, said the breakthrough could change the lives of childless women - although the team is a long way from turning it into a successful treatment.

Crucially, there are already chemicals on the market which have been shown to block microRNAs, and those could be developed to stop this molecular switch from interfering in the IVF process.

‘There are lots of ways in which we can inhibit microRNAs in the lab,’ she said.

‘Eventually drugs might be developed that could improve implantation rates.’

Professor Aplin added: ‘This is one of the hardest groups of women to treat in fertility science and rates are still very low across the board.

‘Repeated IVF cycles are stressful and can be expensive too.

‘Greater understanding of the mechanisms which control success or failure can lead directly to treatments to make IVF cycles more efficient so that infertile couples can start their families.’



