SCIENTISTS are developing a test which could dramatically boost IVF success rates from a single cycle of treatment.

Oxfordshire IVF campaigners welcomed the breakthrough and said they hoped it would help ease stress for couples.

At the moment, only about 30 per cent of IVF cycles worldwide result in a pregnancy, with many failing due to chromosomal abnormalities.

The new technique, being trialled by Oxford University, checks for abnormalities in the developing embryo and also looks at markers which could potentially cause pregnancies to fail.

Researchers hope they can increase success rates from just one cycle of IVF.

Dr Dagan Wells’s team at Oxford has pioneered a technique for checking embryos for abnormalities.

Dr Wells said: “The vast majority of embryos transferred worldwide have no genetic screening and 85 per cent of these fail to establish a pregnancy.

“If you transfer to the uterus embryos that are confirmed to be chromosomally normal and develop well, the chance of producing a child is very high, about 70 per cent.

“But that still leaves 30 per cent that do not make it. Why?

“We need a better understanding of the biology, allowing us to bridge that gap and approach 100 per cent.”

Embryos are grown for five days in the lab and analysed to check the chromosome number.

Only those embryos that are healthy are considered suitable for IVF transfer, increasing the chance of pregnancy to 70 per cent per cycle.

Once developed, the test is likely to cost about £2,000 on top of the cost of IVF.

At the moment, NHS Oxfordshire pays for one cycle of treatment.

Claire and Gary Cousins could not have children naturally because Mrs Cousins went through the menopause at the age of 24. They have since had baby Harry after undergoing one cycle of IVF.

Mrs Cousins, 26, said: “We did not get our hopes up because we knew how often these things fail. It is a stressful time for couples. Anything that makes the process easier and less upsetting for people is a positive thing.”

The test will be particularly useful for older women, who have a higher chance of producing eggs with chromosomal defects, which can cause conditions such as Down’s syndrome.

But it could also benefit younger women – maximising their chances of falling pregnant in each IVF cycle.

The next stage of research will take around a year.