Artificial Shrinkage for Human Blastocyst Prior Vitrification (AS)

Human blastocyst formation begins about 5 days after injecting a single sperm into an oocyte in ICSI cycle or incubation of them in IVF cycle. Human blastocyst consists of cells forming an outer layer called trophotoderm that will form the placenta in case of successful implantation, an inner cell mass which become the fetus, a fluid-filled blastocoel cavity in the center, and a surrounding zone pellucida from which the embryo hatches to implant in the uterus. Human blastocyst contains a large amount of liquid in the blastocoel, which alters the infiltration of vitrification solution during the vitrification procedures leading to ice crystal formation. Therefore, investigators need to compare blastocyst survival, clinical pregnancy and implantation rates between vitrified untreated expanded blastocysts and vitrified blastocysts with artificially eliminated blastocoels by a laser pulse prior to vitrification