Every year, 30,000 new deaf children are born in China, with an incidence of 1 to 3 per 1,000. Hereditary deafness accounts for about 50%, and most of them are autosomal recessive, that is, the affected parents are both carriers of the causative gene but their own hearing is normal. In order to prevent hereditary deafness, the following points should be noted: 1. Marriage law should be strictly enforced to prohibit marriage between close relatives; 2. Genetic testing should be performed before marriage between deaf patients to exclude the possibility of carrying the same disease-causing gene. If both husband and wife have the same mutation, 100% of their offspring will be deaf; 3. Couples who have given birth to deaf children should undergo genetic testing before they get pregnant again, and according to the results, chorionic villus or amniotic fluid specimens should be taken for genetic testing. Our institute has identified 13 cases of affected children. Also, no exposure to deafness medications and deafness-causing microbial infections during pregnancy. 4. Couples who have not given birth to a deaf child and have no family history of deafness should preferably be screened for deafness gene carriers before pregnancy or delivery to avoid having a child with deafness if both partners are deafness carriers. This is part of the primary prevention of hearing defects, so that they can be prevented before they occur. However, most couples do not understand this, so why should pregnant women who do not have a family history of trisomy 21 or who have given birth to a child with trisomy 21 be screened prenatally? Both are actually the same thing! (There are individual differences in the ototoxicity of drugs, not necessarily deafness or hearing loss for the user!) 1. Aminoglycoside antimicrobials: streptomycin, gentamicin, kanamycin, minomycin, neomycin, tobramycin, jessamine, etc. 2.Non-aminoglycoside antibiotics: chloramphenicol, viomycin, erythromycin, vancomycin, capreomycin, chlortetracycline, riduromycin, balomycin, nitisin, polymyxin B, etc. 3.Salicylic acid: aspirin, finasteride, APC, pau taisong. 4.Diuretics: tachyphylaxis, diuretic acid, etc. 5.Anti-tumor drugs: cisplatin, nitrogen mustard, bleomycin, methotrexate, etc. 6.Other: quinine, chloroquine, insulin, iodine, chlorhexidine, etc.