Hearing loss can be present at birth, or it may develop later in life. It may be hereditary, or it may be caused by problems during pregnancy or delivery. It is often very difficult to pinpoint what has caused hearing loss in a particular child. Hereditary factors cause a large percentage of hearing loss in children. The loss may be caused by a defect of the outer or middle ear, but more often the damage exists in the inner ear.
Genetic counseling can be helpful to the family in determining whether heredity is the cause.
Although this information in itself cannot help the child who has the hearing loss, it may assist in family planning and ultimately may be important information for the child. Hearing loss may also be the result of maternal illness during pregnancy, exposure to certain drugs, or complications during delivery. Acquired hearing loss occurs after birth, and may result from prematurity, low birth weight, incompatibility of the Rh factor of blood between the parents, or oxygen deprivation. Illness or accidents may also cause acquired hearing loss. Some illnesses which may cause hearing loss include meningitis, encephalitis, mumps, and jaundice.