Overview of Cryobiology in ART

Abstract

Cryopreservation allows the transfer of a limited number of embryos back to the uterus and the storage of the remaining embryos for future use, thus maximizing the cumulative effectiveness of an in vitro fertilization (IVF) cycle. In addition, cryopreservation makes feasible the postponement of embryo transfer (ET) in a future cycle, thus decreasing the incidence of ovarian hyperstimulation syndrome in high-risk patients, while it maintains the probability of pregnancy. The main problem during embryo cryopreservation is the formation of intracellular ice, which can lead to cell damage and developmental arrest. To overcome this problem, different cryopreservation protocols, such as slow freezing or vitrification, along with different types of cryoprotective solutions, such as propanediol and dimethyl sulfoxide (DMSO), have been developed. In this way the cells are protected against potential injuries occurring at subzero temperatures.