ABSTRACT
In vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) cycles have shown that women have only a finite number of gametes out of a pool of collected oocytes that are viable for generating a term pregnancy. This dem- onstrates the need for simple methods of preimplantation embryo assessment in the prediction of pregnancy rates. In this respect, intensive research has been done at the zygote stage on day 1 of preimplantation development.
