Spontaneous abortion of the first child is commonly caused by the following reasons:1. The most common reason is that the embryo is genetically deficient, which will not grow and will die when it reaches a certain stage.2. Because the mother suffers from some serious medical diseases, such as liver and kidney function problems, it will lead to spontaneous abortion.3. Insufficient progesterone can also lead to spontaneous abortion.4. Uterine dysplasia, such as longitudinal separation of the uterus, can also lead to spontaneous abortion.5. If you have a poorly developed uterus, such as a longitudinal uterus, spontaneous abortion can also occur. 5, because of environmental pollution, noise stimulation and so on may lead to spontaneous abortion, it is recommended that after the abortion must be very good rest, after the body recovers next time before planning to get pregnant to do the appropriate examination, to understand the body’s basic health before pregnancy, is conducive to the eugenics of the birth of a child.