No, this option is not recommended because on day 4 the embryos are at the morula stage. Determining embryo quality at this stage is considerably complicated and, for this reason, it is not possible to determine what's the best moment for the transfer.
Read the full article on: Day 5 vs. Day 3 Embryo Transfer – What Are the Pros & Cons? ( 66).
Bachelor's Degree in Biotechnology from the Technical University of Valencia (UPV). Biotechnology Degree from the National University of Ireland en Galway (NUIG) and embryologist specializing in Assisted Reproduction, with a Master's Degree in Biotechnology of Human Reproduction from the University of Valencia (UV) and the Valencian Infertility Institute (IVI)