Ptotic ears in infants may be caused by genetic factors, abnormal embryonic development, and missing ear cartilage. 1. Genetic factors: the more common cause of droopy ears in infants is genetic factors, if one or both parents have droopy ears, it may also be passed on to the child. 2. Abnormal embryonic development: Due to abnormalities during embryonic development, the cartilage of the auricle may be abnormally folded during development, so the baby will have droopy ears after birth. 3. Missing ear cartilage: Due to the poor development of ear cartilage during embryonic growth and development, babies may have droopy ears after birth. After birth, the cartilage in the ear area may be missing, and the auricle is not supported, so droopy ears are formed. When babies have droopy ears, they should go to the hospital in time to clarify the cause of the droopy ears and standardize the treatment under the guidance of the doctor.