What causes congenital deafness?

The first 3 months of pregnancy are a critical period for the development of the fetal inner ear, and if the mother is infected with a cold, rubella or other viruses or syphilis during this period, it may hinder the normal development of the fetal inner ear and cause congenital hearing loss.

In addition, various toxic diseases during pregnancy, such as diabetes, nephritis, thyroid dysfunction, abdominal X-ray irradiation, long-term deep anesthesia, use of various toxic drugs, threatened abortion, etc., may also affect the development of the fetal inner ear.

Neonatal hearing loss can be caused by maternal pathologies during childbirth, including during and after delivery, such as pre-eclampsia eclampsia, preterm birth, dystocia, umbilical cord around the neck, trauma during childbirth, and neonatal hypoxic asphyxia caused by airway obstruction.

In addition, severe neonatal jaundice, hemolysis, and differences in maternal and child Rh factors can also cause hearing loss in newborns.

When consanguineous marry, the incidence of hereditary hearing loss increases due to the increased chance of both couples having the same deafness gene.

Hereditary hearing loss can occur at birth or become apparent later.

Various toxic diseases during pregnancy, such as diabetes, nephritis, thyroid dysfunction, abdominal X-ray irradiation, long-term deep anesthesia, use of various toxic drugs, threatened abortion, etc., may also affect the development of the fetal inner ear.

Congenital deafness can be caused by genetic factors or non-genetic factors.

1. Hereditary factors. If the deafness gene of the parent is passed on to the offspring, or if the gene is mutated during the development of the embryo, it may cause abnormal development of the eardrum or metabolic disorders, which can lead to the occurrence of hearing impairment. In addition, malformations of the outer and middle ears may cause conductive hearing loss, while hypoplasia of the inner ear may cause sensorineural hearing loss.

It should be noted that congenital inherited deafness may be inherited in an autosomal dominant manner, an autosomal recessive inheritance, or a companion hereditary deafness.

2. Non-hereditary factors. It may be related to the occurrence of infection, poisoning, trauma and other injuries during pregnancy or childbirth.

Genetic mutations, chromosomal variations.

There are two main causes of congenital deafness. One of them is hereditary deafness: sensory deafness caused by a genetic abnormality or chromosome; The second is non-hereditary deafness

In the first trimester of pregnancy, the mother suffers from viral infectious diseases such as rubella, mumps, and influenza, or syphilis, diabetes, nephritis, and natural deafness, for example, the first gene GJB2 gene associated with congenital ** conscious deafness belongs to autosomal recessive inheritance, and homozygous mutations and heterozygous compound mutations are pathogenic. Hearing loss is usually more than moderate.

Congenital deafness is usually caused by problems with the cochlea, and a small percentage is caused by problems with the auditory nerve or auditory center. Most deLEs are caused by genetic problems. The common gene is GJB2.

In addition to genetic issues, some factors during pregnancy can also cause hearing problems. Parents are born deaf, and children are also susceptible to this disease. But all children born are deaf.

Second, close-knit marriages can also lead to congenital deafness. A shortage of fetal ear tissue can also cause congenital hearing loss, but hearing can be restored with surgery.

Non-hereditary deafness: In the first trimester of pregnancy, the mother suffers from viral infectious diseases such as rubella, mumps, and influenza, or systemic diseases such as syphilis, diabetes, nephritis, sepsis, and cretinism, or a large number of ototoxic drugs can make the fetus deaf, and the rh factor in the maternal and infant blood is contraindicated. Congenital deafness can be divided into hereditary and non-hereditary deafness, which can be divided into conductive deafness, sensory deafness, and mixed deafness; Congenital deafness refers to deafness caused by abnormalities or genetic factors during pregnancy and childbirth, and congenital deafness can be divided into hereditary deafness and non-hereditary deafness, which is mainly carried by genes.

Non-hereditary properties are mainly caused by early pregnancy infections, syphilis, rubella virus, ototoxic drugs, and toxic sedatives that can cause fetal ototoxicity through the placenta.

Deafness includes sensory hearing loss and conductive hearing loss. Conductive hearing loss (i.e., conductive hearing loss) is caused by an obstruction in the external auditory canal in the form of sound waves from the outer ear, which includes the external auditory canal, eardrum, ossicle, etc.

Heredity, sequelae left by the fetus when the fetus is in the mother's womb, the expectant mother's illness, etc. There are many causes of congenital deafness, one of which is hereditary deafness, which is caused by genetic abnormalities; There is also the sequelae left by the fetus when the mother-to-be is sick and takes a large number of ototoxic drugs.

Genetic factors, possibly the gene for deafness in the parents. It is also possible that the virus was infected during pregnancy, or that drinking some drugs will affect the child. It is also possible that the fetal pressure is particularly heavy during childbirth, and the impact on the baby is also very bad.

It's because of inherited genes. It can also be caused by viral infections such as mumps and flu in the first trimester, or because of dystocia during labor.

It could be genetics, it could be that the mother was infected with some virus after the time of pregnancy, or it could be that the mother drank some drugs containing hormones, which can cause deafness.

1.Hereditary factors.

Parents are born with deafness, and children are susceptible to this disease. But not all of the children born are deaf. Second, consanguineous marriage can also cause congenital deafness. In addition, congenital deafness can also occur if the fetal ear tissue is malformed, but it can be corrected by surgery to restore hearing.

2.Drug intoxication.

During pregnancy, the mother used ototoxic drugs such as gentamicin and quinine, which can be carried through the placenta to the fetus, resulting in fetal seventh cranial nerve poisoning and deafness. If the mother has been deeply anesthetized during pregnancy, it can also cause hearing damage to the fetus.

3.Disease damage.

If one parent has a sexually transmitted disease, such as gonorrhea and syphilis, it can induce congenital deafness. The mother suffers from rubella and toxoplasmosis infection within three months of pregnancy, and the virus can cross the placenta and pose a threat to the fetus, causing malformations of inner ear development and deafness. Deafness can occur in newborns weighing less than 1,500 grams, suffering from hyperbilirubinemia, severe asphyxia during childbirth, and having purulent meningitis.

4.The process of childbirth.

When the mother is in labor, improper use of forceps can damage the child's hearing organs.

After the drug is applied in the pregnant woman's body, it can directly reach the fetus from the mother through the placenta, and the pharmacological effect has the same period as the mother's. The first 3 months of pregnancy is the critical period when the fertilized egg differentiates most vigorously and the various organs of the fetus are gradually formed. The use of certain ototoxic drugs by the mother during pregnancy is the leading cause of congenital deafness in children.

If a pregnant woman takes ototoxic drugs during the first 3 months of pregnancy, it can cause congenital deafness in the fetus.

The drugs that cause congenital deafness are mostly aminoglycoside antibiotics, among which streptomycin has the greatest damage to the auditory nerve, followed by gentamicin, neomycin, and kanamycin. In addition, vancomycin, puromycin, ristomycin, chunleimycin, polymyxin B, tobumycin, nitamycin, paromomycin and other antibiotics also have varying degrees of ototoxicity, which can lead to congenital deafness of the fetus. Quenin can enter the fetus through the placental barrier, destroying the fetal hearing organ and causing congenital deafness.

Other drugs or chemicals such as sulfonamides, salicylic acids, furosemide, diuretic acid, morphine, cardiorene, alcohol, tobacco, arsenic, lead, phosphorus, mercury, benzene, carbon monoxide, etc. can cause deafness.

At present, there is no drug ** toxic deafness, therefore, the use of drugs during pregnancy should be particularly cautious, especially in the first 3 months of pregnancy, it is best not to use or try to use as little as possible ear poison drugs, all drugs that can be used without use, should not be used, do not advocate for medication without authorization, when you need to use drugs, you should use drugs rationally under the guidance of a doctor, and the medication should not be too long, and the dosage should be minimized.