Chuck Bednar for redOrbit.com – @BednarChuck
Researchers from the Oregon Health & Science University and other institutions have discovered that chromosomal abnormalities occurring in human embryos created for in vitro fertilization can be predicted within the first 30 hours of first-stage cellular development.
As the authors explain in the latest edition of the journal Nature Communications, this discovery could improve the overall success rate of IVF procedures, which has long had just a 30 to 35 percent global success rate. An estimated 50 to 80 percent of embryos created for IVF have some type of chromosomal abnormality, which often leads to a miscarriage.
“Many couples are choosing to have children later in life,” said co-author Dr. Shawn Chavez, an assistant professor in the OHSU School of Medicine, “and this trend is only going to continue.”
“A failed IVF attempt takes an emotional toll on a woman who is anticipating a pregnancy as well as a financial toll on families, with a single IVF treatment costing thousands and thousands of dollars per cycle,” he explained. “Our findings also bring hope to couples who are struggling to start a family and wish to avoid the selection and transfer of embryos with unknown or poor potential for implantation.”
Technique allows for earlier detection of abnormalities
Dr. Chavez and colleagues from Stanford University, University of Valencia and IGENOMIX found that by looking at the duration of the first mitotic phase in the cell cycle, they were able to identify chromosomally normal versus abnormal embryos up to approximately the 8-cell stage.
They also found that, by looking at a single cell level, they could correlate the chromosomal composition of an embryo to a subset of a dozen genes activated before the first cell division. These genes likely originate from egg or sperm, and can be used to predict whether or not an embryo is chromosomally normal or abnormal during the earliest stage of development.
Because of this discovery, doctors and embryologists will be able to quickly identify which embryos are the healthiest for implantation, while also reducing the time that they need to spend cultured in the laboratory before being transferred. Typically, an embryo needs to be implanted within five days of creation, which can be problematic, as chromosomal abnormalities are often not identified until the fifth or sixth day, they noted.
“With assisted reproduction at an all-time high, we want to help more families achieve successful pregnancies,” Chavez said. “IVF has helped countless women all over the world, and we now have the technology and research to improve a couple’s chances of having a biological child of their own. This discovery can potentially increase those chances.”
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