1. Genetic factors: In this case, it is important to pay attention to the parents of the child, as some of them may have multiple clusters of external ear abnormalities in their family. The chance of the next generation to have an abnormal development of the external ear is significantly higher than that of other people of the same age. 2. Drug factor: Some scholars believe that the mother may have applied some special drugs during pregnancy, such as anti-cold drugs and anti-bacterial drugs, and some mothers may have taken vitamin A drugs, which may lead to congenital abnormal development of the fetus. 3. Infection factor These special disease factors can cause the baby to develop ear deformities during development and form appendage ears. 4. Pollution factors: If the mother has long-term contact with polluting substances during pregnancy, such as long-term contact with toxic chemical corrosives or radiation rays, and some parents may make fur products for a long time. This can lead to malformed ear development during the growth and development of the fetus; 5. Other factors: If the mother suffers from metabolic or endocrine system diseases during pregnancy, it can also easily lead to the development of ear attachment in the child.