Yes, the blastocyst on Day 5, we can see for example blastocysts with score 2, sometimes on Day 4. It is a good sign because it starts the blastocyst. It is a good sign.
A grade 2 embryo can still be a good embryo. We grade them as a 2 when either the inner cell mass or the trophectoderm is not perfect. These two different parts of the blastocyst can be graded as an A, B, C depending on the structure, the regularity of the cells, and the number of cells, and of course, if we can choose, we prefer to transfer A embryos. A BB embryo, which would be our class 2 embryos, still have good chances of success, and they should be still considered for transfer, freezing because in some cases, these embryos may achieve pregnancy when the previous ones, the A graded embryos have not worked.
Yes, they have good chances, and depending on whether you are doing egg donation or IVF, the percentage or the implantation rate should be different. It is not the same, class 2 embryo from a 35 years old girl than a grade 2 embryo of a 41. Probably, a grade 2 embryo from a younger may have even better chances of success than the top quality embryo from a 41-year-old woman. That’s basically because of the genetics that in some cases may not be translated into a poorer morphology, so just always consider transferring or freezing these embryos.
