After IVF egg retrieval, the embryo can usually be transferred in about 3 days, and individual need 1~3 menstrual cycles before transfer. 1.3 days or so of transfer: after IVF egg retrieval, the embryos can be transferred at 3 days and 2 days after egg retrieval, and embryo transfer at 6 days (blastocyst stage). Clinical studies have found that the success rate of six-day transfer after egg retrieval is higher than that of three-day transfer after egg retrieval, with lower risks and other advantages. 2.1~3 menstrual cycles: If the endometrium is not suitable for transferring after egg retrieval or there is ovarian hyperstimulation, in this case, embryo culture will be performed first, and after embryo culture, whole embryos will be frozen, and then transferring will be performed in 1~3 menstrual cycles under the guidance of doctors. What time should be transplanted after egg retrieval, must be under the guidance of the doctor, according to the individual situation, to formulate individualized diagnosis and treatment plan for transplantation surgery.