Day 3 cleaving embryos are given two numbers, i.e. 3/8. The first number indicates the grade of the cleaving embryo which is based on several factors including the blastomere size, symmetry, and amount of fragmentation. 3 & 4=Good, 2=Fair, 1=Poor. The number of cells in the cleaving embryo is represented by the second number. Generally 6-8 blastomeres are common for Day 3. 

We use this system to try to determine which embryos will continue development and ultimately lead to a successful pregnancy and healthy child. With that said, just because we grade an embryo as “good” doesn’t mean it will lead to a successful pregnancy, and just because we grade an embryo as “poor” doesn’t mean that it won’t develop into a beautiful baby. The grading is very subjective and we urge clients to not focus all attention on embryo grades.