Day 3, Cell divisions
On day 3, the cells have cleaved once again, so that the plant embryo consists of 8 cells. The embryos are once again investigated in the embryoscope for cleavage abnormalities, and we follow the development of each single embryo carefully.
Some embryos have stopped cleaving. This is a bad sign. The embryologist looks at the number of cells in each embryo. She also assesses the size of the individual cells and looks at whether there are nuclei in the cells. In addition, she estimates how much fragmentation there is and looks at the thickness of the zona pellucida.
If there are more high quality embryos than you want transferred back into the uterus, we continue embryo culture.