Principles and Technology of Embryo Transfer Embryo transfer is an assisted reproductive technology. Its principle is to transplant embryos cultured in vitro into the mother\’s body. After artificial insemination or artificial conception, the embryo is cultured in vitro until the embryo differentiates into the blastocyst stage, and then the blastocyst is transplanted into the mother\’s uterus. If the blastocyst can implant in the uterus, pregnancy will occur, which is considered a successful transplant. The embryo transfer technology mainly includes embryo culture, blastocyst