It is always preferred to freeze A and B quality embryos, although it is also possible to vitrify C quality embryos.
However, the decision to freeze the D quality embryos will depend on the center itself. These embryos have low quality, as well as the probability of survival after thawing. In these cases, it is usually decided to leave the embryos in culture until day 5-6 of development to study their evolution.
Read the full article on: How To Choose The Best Embryo? Characteristics & Techniques ( 65).
Marta Barranquero Gómez
Graduated in Biochemistry and Biomedical Sciences by the University of Valencia (UV) and specialized in Assisted Reproduction by the University of Alcalá de Henares (UAH) in collaboration with Ginefiv and in Clinical Genetics by the University of Alcalá de Henares (UAH).