DAY 2 & DAY 4
The embryos are not checked on day 2 and day 4 to avoid disturbing the embryos in culture. Day 2 is only checked if any of your eggs required day 1 ICSI.
Number of cells:
6 to 8 cells in a day 3 embryo is considered normal cell division.
Less than 6 cells the embryo is considered having poor embryo development. These embryos have a low chance to becoming a blastocyst.
>10 cells and Morula (MOR) are embryos that show faster embryo development, but they still have a possibility to become blastocyst. These embryos, >10 cells and Morula, do not have a specific embryo grading description.
Grade 1 is considered the highest score, meaning it has equal symmetry and no fragmentation.
Grade 2 is considered the second-best embryo grade. These have either uneven symmetry and/or slight fragmentation.
Grade 3 is considered below average embryo quality.
Grade 4 is considered the worst score, meaning it has a poor embryo quality.
Embryos containing the number of cells expected (i.e. 6-8 cells on day 3) and either grade 1 or grade 2 have the greatest possibility of becoming blastocysts. If the embryos do not have the number of cells expected, the possibility of becoming a blastocyst is reduced.
Embryos containing the number of cells expected but are grade 3 have a moderate possibility of becoming a blastocyst.
Embryos with less than the number of cells expected on day 3 and are grade 3 have a low possibility of becoming a blastocyst.
Any embryos with grade 4 have a poor possibility of becoming a blastocyst.
*Fragmentation: : Is a small portion of the cytoplasm (the inside of the cell) that breaks off and forms what we call fragments.