After the eggs are taken out, they are incubated with sperm in vitro. Each egg needs about 100,000 sperm. After fertilization, the fertilized eggs divide into early embryos, i.e. embryo transfer (ET) can be carried out when 2-8 mitotic balls are formed. At this time, about 48 hours after the eggs are picked up, the time can also be changed slightly according to specific conditions. If one day is postponed, it may also be better. Embryo selection. If it is too early, the intrauterine environment may not be conducive to embryo acceptance. Generally, in the first cycle of stimulation cycle, experimental transplantation is carried out in outpatient clinic to understand the location of the uterus, the angle between the cervix and the uterine body and the length of the sub-organ cavity, and slightly dilate the cervix. After sterilizing the vulva during transplantation, the speculum exposes the cervix, wipes it clean, and then re-expand Secondly, wipe the cervix and fornix and cervical canal with culture liquid, and remove the mucus as much as possible. The movement should be as gentle as possible to reduce the stimulation of uterine muscles. Introduce embryos into the uterine cavity with a special transfer tube. Introduce embryos 0.5 cm away from the bottom of the uterus. After a minute, turn your head 90 degrees to shake off a drop of liquid that can not be dripped, and then repeat. After the catheter is removed, the embryo is examined under a microscope. After transplantation, patients can lie on their backs, hips are raised and the uterus is prone. The purpose is to keep the implanted embryo above the uterine cavity. It can urinate for about 3-6 hours and avoid urine retention. HCG 5000 countries were injected on the day of transplantation. Progesterone and progesterone 30 mg were injected daily. If HCG was negative in urine 14 days later, progesterone would stop injecting. Pregnant women would continue to decrease gradually until fetal heart rate was visible by B-mode ultrasound. For those with excessive follicles, which may lead to ovarian hyperstimulation syndrome, HCG should not be used.