Assisted hatching is indicated in some particular cases. For instance, in cases of embryos with a thickened zona pellucida or with an abnormal colour of the zona pellucida.
Tag: number of cells
Embryos can be classified in 4 categories –from A to D– ranging from best quality to least developed embryos. This classification is mainly visual and rather subjective, but there are also several studies to identify their metabolic activity.
Assessment of embryo quality is determined by checking their development once a day from the moment of fertilisation to the day in which embryo transfer is performed –on day 3 or day 5, depending on the case.