Embryonic development during in vitro fertilization (IVF) is assessed at various stages, including day 3, when embryos typically consist of 6-8 cells. An embryo with only 5 cells on day 3 is considered to be developing at a slower pace than expected. Whether such an embryo can achieve a developmental stage comparable to its counterparts is a key consideration in determining its viability for transfer.
The rate of cell division in early embryonic development is a significant indicator of its potential for successful implantation and subsequent pregnancy. Historically, embryos with optimal cell numbers on day 3 were prioritized for transfer. However, advancements in assisted reproductive technology have prompted investigations into the developmental potential of slower-growing embryos. Evaluating their capacity for subsequent growth and implantation is important for maximizing the chances of a successful IVF cycle.