A new IVF screening technique could double the success rates for some women, a study has found. Defects in the number of chromosomes in an embryo are thought to be a major cause of miscarriage, with older women being more at risk.
A new IVF screening technique could double the success rates for some women, a study has found.
Defects in the number of chromosomes in an embryo are thought to be a major cause of miscarriage, with older women being more at risk.
Healthy embryos should have 23 pairs of chromosomes, but some have more or less than this number.
The new technique, comparative genomic hybridisation (CGH), is the most advanced way yet of counting chromosomes and could soon be available in the UK.
Previous methods have only allowed around half of the chromosomes per embryo to be counted accurately.
In the latest study, experts from Oxford University analysed the results of a clinical trial carried out by researchers at the Colorado Centre for Reproductive Medicine in the US.
A total of 23 patients took part, aged 37 on average, with the age range being 30 to 42. Each had suffered an average of 1.9 failed IVF cycles before enrolling in the trial.
Researchers fertilised eggs from the women and allowed embryos to mature for five days until they reached the blastocyst stage.
Analysing the embryos using the latest technique meant that all 23 had at least one normal blastocyst for transfer. A total of 50 embryos were transferred in 23 cycles.
Of the women, 21 fell pregnant (91%) and 20 (87%) had a clinical pregnancy (where a foetal heartbeat is confirmed by ultrasound).
Experts predict the live birth rate will be 78%. This compares with an anticipated 60% for the same patients without embryo screening.
Two women have already given birth and four more are due to by the end of the year.
Dr Dagan Wells, from Oxford University, said the results, being presented at the American Society for Reproductive Medicine conference in San Francisco, were "phenomenal".
He said: "This is more than twice the implantation rate seen without CGH screening, indicating that success rates of single embryo transfer can be doubled using this technique."
Dr Wells said he was ready to begin a trial in the UK and had applied for a licence to start offering CGH to UK patients, at a cost of about £2000 per screening.
"Chromosomal abnormalities are the main cause of implantation failure and miscarriage, and a way of detecting them should improve success rates," he said. "There is a dramatic change in implantation rate with this technology."
Dr Mandy Katz-Jaffe, from the Colorado Centre for Reproductive Medicine, said: "Dagan and I are very excited because this really holds promise for single embryo transfer.
If you have one blastocyst that is chromosomally normal, we can give a 60% chance of implantation. You don't need to have many blastocysts.
"The effect on those patients who have conceived has been beyond anything I can describe."
