Embryo 'looks' are deceiving

A large study was published recently comparing embryo morphology and the genetic make-up of human embryos. The research shows that the visual appearance of an embryo (or morphology) only weakly predicts the health of the embryo.
Many embryos with a healthy appearance were shown to have an abnormal chromosome pattern (or aneuploidy). Embryos with an abnormal chromosome number generally fail to implant, lead to miscarriages or may cause serious abnormalities in the baby.
Embryos of optimal morphological quality on day 3 of development were significantly more likely than day 5 embryos to have chromosome abnormalities.