There are many reasons for the failure of fresh embryo transfer, the more common ones are embryonic factors, uterine factors, immune factors and so on. 1. Embryonic factors: If the quality of embryo is not good, or the embryo has some chromosomal diseases, the embryo may not be able to implant in the process of transfer, and even if the implantation is successful, there will be miscarriage, resulting in the failure of the transfer. 2. Uterine factors: uterine factors include many aspects, if a woman’s endometrium is too thin or too thick, are not conducive to the fertilization of the egg implantation failure, in addition to the presence of polyps or tumors in the endometrium will also affect the implantation. 3. immune factors: if the fresh embryo transfer repeatedly failed, also consider some immune factors, such as the presence of natural killer cells. There may be other reasons for the failure of fresh embryo transfer, it is recommended to go to the hospital in a timely manner, improve the examination to clarify the cause of the disease, and then give targeted treatment or treatment under the guidance of the doctor.