20/02/2021
Abnormal embryos diagnosed by PGS / PGT-A can give rise to normal healthy births. PGS maybe unnecessary and a waste of money!
Please take note of the controversy surrounding PGS with regards to Mosaic embryos, which have a mixture of normal (euploid) and abnormal (aneuploid) cells. These are often tested to be genetically abnormal by PGS, but in fact can give rise to normal healthy births.
As seen in the attached diagram of a blastocyst-stage human embryo, the ICM gives rise to the embryo, while the TE gives rise to the placenta and yolk sac. Testing a few cells from the TE only gives you a probability about what's going on in the ICM. An embryo with abnormal (aneuploid) TE but normal ICM most likely will still make a healthy baby.
Hence, by discarding such mosaic embryos that are tested abnormal during PGS, one would lower the cumulative chances of IVF success.