ABSTRACT
Since the birth of the first in vitro fertilization (IVF) baby in 1978, there have been numerous advances in the field of assisted reproductive techniques (ART), including improvements in hormonal stimulation regimens, the formulation of optimal embryo culture media, and refinements in embryo replacement techniques. As a result, it has become a common occurrence in many ART programs to have patients with large numbers of good-quality embryos or blastocysts available for transfer. In addition, there are times when patients with certain medical conditions may need to freeze all conceptuses in lieu of transfer. Thus, the need for an adequate embryo cryopreservation program in most centers has evolved from one of luxury to one of necessity.
