Reuters (11/9) reports, “Embryos classified as mosaic are capable of producing healthy babies and should be considered for transfer when a euploid embryo is not available, say fertility specialists.” This mosaic-embryo transfer (MET) following preimplantation genetic testing for aneuploidy (PGT-A) “has become more common based on mounting evidence that these embryos have reproductive potential.” Researchers “at NYU Langone Fertility Center in New York City reviewed all MET cases occurring at their center since September 2015 in which an ongoing pregnancy was documented,” and “of the 35 patients who had mosaic embryos transferred, none of those fetuses had chromosomal abnormalities, suggesting that the risk for chromosomal syndromes associated with MET is ‘likely overestimated,’ the team reports in an abstract presented at the American Society for Reproductive Medicine (ASRM) annual meeting.”
For the reason stated above, Mosaicism and other evidence that embryos classified as abnormal through genetic testing could produce normal embryos, JCRM has taken a very conservative approach to this testing. Once labelled abnormal through testing, it becomes extremely difficult to transfer these embryos even if desired at a later time. Currently, we recommend considering PGT-A only in patients 38 yrs old and older and only in very selected cases. We find it very difficult to consider the possiblity that we are discarding embryos that could produce healthy babies. For further questions discuss with your provider.
Michael D. Fox, MD
Jacksonville Center Reproductive Medicine
Advanced Reproductive Specialists