In vitro fertilization is the use of artificial methods to fertilize egg cells and sperm outside the body, and early embryonic development, and then transfer to the mother’s uterus for development and birth of a baby. Steps performed in IVF: 1. Controlled superovulation: Since the length of natural menstrual cycle varies from person to person and varies from cycle to cycle in the same patient, it is not easy to schedule egg retrieval, and only one dominant follicle develops in the natural cycle, only one embryo can be formed after fertilization, and the pregnancy rate of transferring one embryo is very low. Therefore, controlled superovulation is needed to enhance and improve ovarian function in order to obtain multiple healthy eggs regardless of the natural cycle, to provide multiple embryos for transfer, and to synchronize the corpus luteum development with the endometrial function as much as possible. Controlled ovulation is generally achieved by first using GnRHa to bring down the FSH and LH in the body, then administering HMG or FSH ovulation drugs to stimulate the growth of follicles in the ovaries, and adjusting the dose of the drugs according to the patient’s responsiveness to the drugs. 2. Follicle monitoring: In order to evaluate the effect of ovarian stimulation and to determine the timing of egg retrieval, the follicle size should be monitored by vaginal ultrasound and the E2 value (estrogen) should be checked with blood sampling to adjust the dosage of medication. When two to three or more follicles are larger than 1.8 cm in diameter and the number of follicles above 1.4 cm is comparable to the E2 value, human chorionic gonadotropin (hCG) can be injected to promote follicle maturation. Eggs are retrieved 34 to 36 hours after hCG injection. 3. Egg retrieval: The most commonly used method of egg retrieval is under local anesthesia, guided by vaginal ultrasound, the needle is passed through the vaginal fornix to the ovaries and the eggs are immediately transferred under a microscope to a Petri dish containing embryo culture fluid and incubated in a 37°C incubator. 4. Sperm retrieval: The sperm is removed on the same day as the egg retrieval. Wash your hands before sperm retrieval and use the masturbation method to retain the semen. The small cup given is sterile and do not touch the rim of the cup or the inside of the cup when retaining it. The extracted semen is processed by upstream method or density gradient centrifugation method. 5. In vitro fertilization: 4 to 5 hours after egg retrieval the treated sperm and eggs are placed in the same Petri dish and co-cultured for 18 hours, then fertilization can be observed under a microscope. If the sperm quality is too poor to allow natural fertilization, fertilization must be forced by microinjection. 6.Embryo in vitro culture. 7.Embryo transfer. 8.Progesterone supplementation after embryo transfer. 9.Morning urine test on the 14th day after embryo transfer to determine if pregnancy. 10.After 14 days of pregnancy, ultrasound will be performed to check the number of fetus and embryo implantation site.