The purpose of transferring frozen embryos three days later is to advance the luteal support treatment to synchronize the development of the embryo with the development of the lining, which is conducive to the embryo’s implantation. Frozen embryo transfer is a method of in vitro fertilization-embryo transfer where frozen embryos are thawed and transferred into the uterine cavity for implantation to achieve conception. The key before the frozen embryo transfer is to do a good job of endometrial preparation, to follow the doctor’s advice to give three days of progesterone treatment in advance, so that the development of the endometrium and the development of the embryo synchronization is conducive to embryo implantation in the uterine lining. After the frozen embryo transfer, it is necessary to pay attention to not to carry out strenuous activities and heavy physical labor, you can reduce the activities, but do not need absolute bed rest, light diet, but also follow the doctor’s instructions in the transfer of about 2 weeks after the blood or urine pregnancy test to confirm the pregnancy, and in the transfer of about 4 to 5 weeks, ultrasound to clarify the pregnancy in the uterus.