When one starts an in vitro fertilisation (IVF) treatment, one of the most frequent concerns is the number of high quality embryos that can be obtained.

This number is variable and depends on several factors such as the ovarian reserve and gamete quality (egg and sperm). Once the eggs are fertilised, they are considered embryos, which begins after their early division. The embryo division is observed in the IVF laboratory on a daily basis and is key information to determine the embryo quality. The Spanish Association of Reproductive Biology (ASEBIR) establishes a classification according to various observed morphological parameters, which indicate the embryo quality according to their capacity to implant in the womb. […]