ABSTRACT
Morula or blastocyst stage marks the switch from a cell cluster of individual blastomeres to a relatively smooth mass with indistinguishable cell outlines capable of actively regulating its internal environment. Thus, any prolongation of in vitro culture will allow for a more accurate prediction of developmental capacity. Other potential advantages of blastocyst culture include synchronization between developmental stage of the embryo and the uterine milieu, reduction of multiple pregnancy rate, or indirect selection of chromosomal anomalies.
