Researchers are testing whether high-throughput DNA sequencing can help screen out abnormal embryos during in vitro fertilization. In a trial, researchers will use DNA sequencing to count the number of chromosomes in each of the embryos they create by fertilizing a woman’s eggs in a dish. An abnormal number of chromosomes is the most common reason for IVF to fail, experts say, and as many as 30 percent of fertilized human eggs have such abnormalities. By selecting only those embryos with the normal number of chromosomes to transfer into the uterus, doctors hope to improve the success rate of IVF.
Traditionally in an IVF procedure, doctors visually inspect embryos and then transfer those that appear healthy after a few days of growth—often more than one at a time, because many of the embryos won’t result in a successful pregnancy. If multiple embryos do implant successfully, however, it can be risky for both them and the mother, says Richard Scott, a reproductive endocrinologist and lead researcher in the trial, which is being conducted at Reproductive Medicine Associates of New Jersey.
To reduce such risks, some clinics, including Scott’s, are moving toward transferring only a single embryo, and new DNA analysis technologies are helping to ensure that they pick the most viable and healthy one. Researchers have already shown that other methods of chromosome screening can improve the success rate of IVF. DNA sequencing offers a more affordable way to do such tests because samples from multiple embryos can be analyzed simultaneously. That gain in efficiency lowers the cost of the procedure and could make chromosome screening feasible for more couples
Time lapsed photography for IVF embryo screening in the UK
The method, reported in Reproductive BioMedicine Online, can be used to select embryos at low risk of defects.
Scientists at the CARE fertility group say such informed selection can improve birth rates by 56%.
In standard IVF, embryos are removed from the incubator once a day to be checked under the microscope. This means they briefly leave their temperature-controlled environment and single daily snapshots of their development are possible.
Using the time-lapse method embryos don’t leave the incubator until they are implanted allowing 5,000 images to be taken.
“Removing embryos from the incubator potentially exposes them to damage, so it must be a good thing to be able to look at the pattern of development over time.
Around a dozen private and NHS clinics were using time-lapse embryo imaging in 2013. It adds around £750 ($1200) to the cost of IVF.