Quality Management of Gamete and Embryo Cryopreservation

The cryopreservation of gametes and embryos is one of the routine practices within the IVF laboratory. The increasingly sophisticated gamete and embryo cryopreservation technology secure the safety and effectiveness of assisted reproduction treatment. With the widespread use of the whole embryo freezing strategy, single blastocyst implantation strategy, and the development of preimplantation genetic testing technology, embryo cryopreservation has become a crucial part of assisted reproduction treatment. In this chapter, we will have a comprehensive overview of the various aspects of cryopreservation involved in the IVF laboratory: we will introduce the basics involved in cryopreservation, i.e., the forms of damage to gametes and embryos during cryopreservation, as well as the principles of cryoprotectants; we will outline the steps and principles of slow freezing and thawing; we will explain in detail the principles and steps of vitrification and post-vitrification thawing of eggs and embryos; we will describe the steps and clinical outcomes of sperm cryopreservation; we will list and compare open versus closed cryopreservation carriers; we will explain specifically the artificial shrinkage and assisted hatching techniques involved in embryo cryopreservation; and finally, we will discuss matters related to the management of cryostorage room.