Grading

Ashley • 36; #ivfsuccess 💙💓

Can someone explain grading to me. I still don’t fully understand and I just had a failed FET (4ab). My son whose 18 months was a 4aa.

I now have 3 frozen embryos left. 4bb and two 5bb. Are 5bb good?

I asked this question before a different way in a different group but didn’t get a clear answer.