With the advancement and development of medicine, the causes of habitual abortion have been basically identified. However, after excluding congenital factors such as chromosomal abnormalities and congenital malformations of the uterus, there are still many unknown acquired factors that can also cause miscarriage. 26-year-old Li Songyan is an unfortunate mother. When she was pregnant, because the weather was too hot, Li Songyan stayed in an air-conditioned room every day with her big belly. At first, I just felt that my nose was a little blocked and my throat was not very good.