Fresh embryo transfer is also called fresh embryo transfer. Most women have no reaction on day 4 of fresh embryo transfer, while individual women have mild abdominal pain or a small amount of bloody discharge, and may also experience ovarian hyperstimulation syndrome. Fresh embryo transfer is a process in which the egg and sperm are fertilized in vitro to form an early embryo 3 days after egg retrieval, and the embryo is transferred directly in the fresh cycle. Day 4 of fresh embryo transfer is relatively short and most women’s bodies will not react. Fresh embryo transfer usually starts to implant in 3 to 5 days. Some women may experience mild abdominal pain and a small amount of bloody discharge on the 4th day of fresh embryo transfer, which is usually physiological and does not require special treatment, and will be relieved naturally after 2 to 3 days. On the 4th day of fresh embryo transfer some women may experience ovarian hyperstimulation syndrome, which is a common complication of assisted reproduction technology, women may experience abdominal distension, nausea, vomiting, chest and abdominal fluid, breathlessness and other uncomfortable reactions. Each woman’s physical condition is different, and the reaction after fresh embryo transfer is also different, and it is recommended to seek medical treatment in time for serious cases.