Age is a key factor influencing the success rate of IVF. 25-35 years old is the prime age for women to have children, and the success rate of IVF is higher at this stage. There are various causes of infertility, among which endometriosis, polycystic ovary syndrome and other causes of infertility are lower than the success rate of IVF in other patients. Fluid in the fallopian tubes can also significantly reduce the embryo fertilization rate and pregnancy rate. 3. Endometrial thickness The endometrium is important for embryos and is an important place for embryo implantation. If the endometrium is thick enough, with rich blood flow and good cell division, it will increase the rate of embryo implantation, on the contrary, if the endometrium is too thin, embryo will not be easily implanted. If the endometrium is damaged, myometriosis, etc., it may cause the embryo to not be able to be bedded and affect the success rate. 4. Psychological state The influence of psychological state is also very crucial. Excessive psychological tension may cause endocrine disorders, which may lead to difficulties in embryo implantation, so infertile women should maintain psychological balance and be optimistic and open-minded during the IVF treatment. The quality of embryos is a key factor in the success rate of IVF, as high quality embryos are easy to succeed and poor quality embryos have a high failure rate. Clinically, the quality of embryos can only be distinguished by their morphology.