Congenital deafness is a hearing loss that is already present at birth. Congenital deafness can be both hereditary and non-hereditary; it can be both sensorineural and conductive deafness; and it can be either unilateral or bilateral involvement. The factors leading to congenital deafness can be broadly classified into two categories: hereditary and non-hereditary factors. The hereditary factors are mainly nuclear and mitochondrial genetic variants, and the inheritance of deafness can be autosomal dominant, autosomal recessive, sex-linked, or matrilineal. The deafness can also be non-syndromic deafness without other organ abnormalities or syndromic deafness with other organ abnormalities. The non-genetic factors that cause congenital deafness are the various influences during pregnancy and the influences on the newborn during delivery. Influences during pregnancy include: (1) infectious factors, such as rubella virus infection, toxoplasma infection, syphilis spirochete infection, herpes simplex virus infection, cytomegalovirus infection, etc.; (2) use of drugs that affect the development of the fetal auditory system during pregnancy, such as hypoglycemic and ototoxic drugs (aminoglycoside antibiotics, antimalarial drugs, and dozens of others). If these drugs are used in early pregnancy, they are more likely to cause abnormal fetal development; (3) Pregnant women have diseases, such as hypothyroidism, the fetus may be born with congenital deafness; (4) Environmental factors affect the pregnant woman and the fetus, such as radiation damage, etc. Factors that can easily lead to deafness during labor and delivery include: (1) fetal or neonatal hypoxia and asphyxia; (2) preterm birth; (3) cranial trauma; (4) low birth weight; and (5) hemolytic jaundice of the newborn.