A new study by Stanford bioengineers and physicians finds that measuring the rigidity of an hour-old fertilized egg can predict its viability more accurately than current methods at this early stage. The technique, published online on February 24, 2016 in Nature Communications, could potentially vastly improve the success rate of single-egg in vitro fertilization (IVF), which consequently could improve the prognosis for both mothers and babies. The open-access article is titled “Human Oocyte Developmental Potential Is Predicted by Mechanical Properties Within Hours After Fertilization.” Current IVF embryo screening is a relatively qualitative procedure. Scientists fertilize an egg with sperm, and five or six days later, once the embryo has reached the 60-cell to 100-cell blastocyst stage, scientists evaluate the embryos' morphology and the rate at which cells have been dividing. The best-looking embryos that have been dividing at the "best" rate are then selected for transfer. Plucking a few cells from the blastocyst for genetic testing can increase the odds of choosing a successful embryo, but this invasive procedure can stress the embryo, even though the sample is taken from cells that will eventually form the placenta. In either case, the results are still uncertain, and the roughly 70 percent failure rate means that doctors typically implant multiple embryos into a mother's womb, in hope that one will take hold. This can often lead to complications. "A lot of twins are born because we don't know which embryos are viable or not, so we transfer several at one time," said lead-author Livia Yanez, a bioengineering Ph.D. student in Dr. David Camarillo's lab at Stanford. "This can increase the risk of neonatal mortality and cause complications for babies and the mothers.
Login Or Register To Read Full Story