Congenital hearing impairment

Congenital deafness, i.e. no sound can be heard after birth, which can occur in one ear or both sides, with varying degrees. The main causes of congenital deafness are as follows:

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1. Congenital deafness caused by genetic factors

Hereditary deafness is caused by genetic material, i.e. genetic and chromosomal abnormalities. It is possible that parents’ heredity or birth of close relatives may affect their children’s hearing. Parents have congenital deafness, and their children are susceptible to it. But not all the children are deaf. Although some parents have no deafness, the incidence of deafness of their children is higher if they marry close relatives. In addition, it also has auricle deformity, middle ear deformity, atresia of external auditory canal, hypoplasia of internal ear, or mental disorder.

2. Congenital deafness caused by pregnancy

Maternal infection causes fetal congenital deafness. During pregnancy, especially the first three months, it is the most critical time for fetal organ formation and also the critical period for the development of auditory helix. During this period, pregnant women are infected with rubella virus, giant cell virus, Toxoplasma gondii, influenza virus, mumps virus, etc., which can be transmitted to the fetus through the placenta, or because of the toxic effects of other substances, such as streptomycin, gentamicin, kanamycin and other drugs taken by the mother at the early stage of pregnancy, which hinders the normal development of inner ear sensory epithelium, resulting in congenital deafness, and often sensorineural ear Deafness. Most of the children with iodine deficiency disease and endemic cretinism are accompanied by deafness or deafness. In addition, various toxic diseases, diabetes, nephritis, abdominal X-ray irradiation, long-term deep anesthesia and various toxic substances in pregnancy can affect the development of fetal inner auditory nerve, thus causing congenital deafness.

3. Congenital deafness caused by prenatal damage

It includes the diseases that the mother has been deeply anesthetized during pregnancy, the diseases occurring in the period of labor and the days after delivery, such as toxemia during the late pregnancy, trauma during delivery, premature delivery or dystocia, which may damage the baby’s cochlea and cause deafness, such as hypoxia, cord strangulation, airway blockage, etc. A small number of newborns with anemia, nuclear gangrene and scoop Rh factor incompatibility can also lead to deafness.