Thousands of infertile couples could benefit from a new IVF procedure that can dramatically improve the success rate of having a baby through artificial reproduction.
Scientists believe they can double or even triple the proportion of healthy babies born as a result fertility treatment with a relatively simple technique that takes a series of time-lapse photographs of the developing IVF embryos.
On average only about 24 per cent of IVF embryos implanted into women in the UK lead to live births but the researchers believe this could be increased to 78 per cent using the new technique for selecting the best embryos.
“I believe it is the most exciting breakthrough we've had in probably 30 years,” said Professor Simon Fishel, managing director of the CARE Fertility Group, where the technique was developed.
“Every IVF practice in the world is unintentionally and unwittingly putting back into the womb unviable embryos that don't make babies,” Professor Fishel said.
“We hope to see a paradigm shift in terms of IVF. It's a game changer for everybody to have such an uplift in live birth rates. This is the beginning of something revelatory,” he said
Each year, licensed clinics in Britain carry out about 60,000 IVF treatments but most of them end in failure, causing immense emotional upset to couples, many of whom have paid between £5,000 and £10,000 for each treatment cycle.
The new procedure, which costs £750, identifies the best embryos to be implanted into the womb based on the time it has taken to develop between two key stages in the early life-cycle of the embryo.
Thousands of time-lapse pictures are taken during the first few days of an IVF embryo's life and these are used to identify the time between the first appearance of the fluid-filled cavity, called the blastula, and the final moment before the embryo “hatches” from its protective shell.
Scientists have discovered that when this period lasts longer than about six hours, the IVF embryo is likely to be carrying an abnormal number of chromosomes, called aneuploidy, which will lead to a failure of the pregnancy.
A preliminary study, published in the journal Reproductive Medicine Online and based on a retrospective analysis of 88 IVF embryos of 69 couples, found that the time-lapse technique could have improved the success rate of life births in this particular group of patients from 39 per cent to 61 per cent.
Even better success rates can be expected once the procedure is refined and applied to the wider population of infertile couples seeking IVF treatment, Professor Fishel said.
“Our work has shown that we can easily classify embryos into low or high risk of being chromosomally abnormal. This is important because in itself this is the largest single cause of IVF failure and miscarriage,” he said.
“The beauty of this technology is that the information is provided by a non-invasive process. So far we have seen a 56 per cent uplift compared to conventional technology, giving our patients the equivalent to a 78 per cent live-birth rate,” he added.
Normally, IVF embryos in an incubator are checked manually each day by embryologists but the time-lapse cameras are able to do this automatically by taking pictures every 10 minutes without interfering with embryo development, said Alison Campbell, embryology director at Care Fertility in Nottingham, who developed the computer algorithm controlling the analysis.
“With time-lapse we have the ability to view more than 5,000 images over the same time period to observe and measure more closely each stage of division and growth. As a result of continuous monitoring we have demonstrated that delays at defined points indicate abnormal development,” Ms Campbell said.
Martin Johnson, a fertility expert and editor of the journal where the work is published, said further “prospective” studies comparing the technique to existing methods of embryo selection are still needed before the procedure is recommended as standard treatment. “There are caveats with this research….and for these reasons we have to be cautious,” he said.
Sue Avery, director of Birmingham Women's Fertility Centre, said: “Unfortunately the study does not compare this exciting new approach with standard practise in embryology in which embryologists already look for the best embryos to place in the womb. Until the new technique is compared to current practise we cannot know whether different embryos are being chosen.”
Egg timing: Key stages
The developing embryo (image one, above) goes through two key stages when the fluid-filled cavity or “blastula” first forms (image two) and when the blastula is fully formed before the embryo “hatches” (image three).
The time between the two is used to judge whether the embryo is viable, with no defects in chromosome numbers. If the period is longer than six hours, the embryo is at high risk of abnormal chromosomes, which will inevitably lead to complications. Time-lapse photographs can indicate which embryos have a shorter time-period between these two points, and so which embryos are best for implantation into the womb.