American Journal of Human Genetics, Capalbo et al.: “Mosaic human preimplantation embryos and their developmental potential in a prospective, non-selection clinical trial”.

Results summary: out of 484 euploids embryos, 282 low-grade mosaics, and 131 medium-grade mosaic embryos, birth and miscarriage rates were similar. Obstetric and neonatal outcomes were also similar. 

Read the paper here: https://www.cell.com/ajhg/fulltext/S0002-9297(21)00412-2

And here’s the comment of GeneraLife co-authors: 

“This study – say Filippo Maria Ubaldi and Laura Rienzi, scientific directors of GeneraLife group, co-authors of the new paper – shows how much pre-implantation genetic test is reliable and useful for optimizing IVF results. Data show the absence of a concrete clinical utility deriving from not transferring embryos with a low degree of mosaicism in the uterus: embryos with these molecular results following pre-implantation genetic test have in fact shown pregnancy and miscarriage rates absolutely comparable to euploid embryos. We are convinced that this paper will have an immediate impact on the clinical practice, leading to an update of the guidelines and recommendations drafted by the scientific societies in this field, allowing IVF  patients to improve their decision-making process”. “One of the pillars we base our work on – confirms Danilo Cimadomo, GeneraLife Science and Research Manager – is to invest in the implementation of new technologies in IVF, but only following a rigorous pre-clinical and clinical validation process. This study lays new foundations, grounded on robust scientific evidence, on the choice of not reporting the possibility of mosaicism based on a single embryonic biopsy: these blastocysts are, indeed, most probably chromosomally normal”.