There are many reasons for miscarriage, including infection, the development of the embryo itself, nutritional factors, disease, mental state and so on. 1. The development of the embryo itself: this is generally the result of survival of the fittest, sperm or egg of poor quality or defective, the formation of the fertilized egg will also affect the development of the embryo at a later stage, follow the principle of survival of the fittest, there may be miscarriage. 2. The mother’s own disease: if the mother has congenital dysplasia or uterine deformities, or organic lesions of the uterus, can also trigger miscarriage. At the same time, if the mother suffers from high blood pressure or diabetes and other underlying diseases, can also lead to complications, resulting in miscarriage. 3 infection: if the embryo in the process of development, inadvertent intrauterine infection, then it will also lead to the occurrence of miscarriage. 4. Psychological emotions, nutrition: during pregnancy, pregnant women should maintain a comfortable mood. Long-term adverse emotional stimulation, excessive tension, anger or depression may also lead to the occurrence of miscarriage, at the same time, if there is insufficient nutritional intake, then it will also affect the development of the fetus. There are many factors that can trigger a miscarriage, so if you notice any abnormalities during pregnancy, it is recommended that you seek medical attention and treatment in a timely manner.