Question
What are the risk factors for permanent childhood hearing loss?
Answer
Some children are born with permanent hearing loss. Other children may have normal hearing at birth, then acquire a hearing loss. In other words, the hearing loss is delayed in its onset; it may start months later in infancy or even years later in early childhood or beyond. Some children may have a hearing loss that increases gradually over time. This is referred to as a progressive hearing loss. They could have a minimal hearing loss at birth that isn’t even detected by the newborn hearing screening, and the hearing loss worsens during the preschool years and sometimes the school years. If you work with preschool children, it is important to know that even though a child may have passed a hearing screening or hearing exam at birth, he or she might have a hearing loss now or develop one. That’s why it is important to know the risk factors for hearing loss.
These risk factors are often available in the child's records; certainly, a mother or pediatrician almost always is aware of them. By identifying risk factors and getting children’s hearing evaluated, we can detect hearing loss in preschool children as soon as it begins to emerge.
The 2007 Position Statement: Principles and Guidelines for Early Hearing Detection and Intervention Programs by the Joint Committee on Infant Hearing is an excellent resource for information on childhood hearing loss. Appendix 2 includes risk factors associated with permanent congenital, delayed-onset, or progressive hearing loss in childhood. I recommend keeping this list of risk factors easily accessible in your early childhood setting so that everyone working with children can be aware of them. They are as follows:
Caregiver concern about hearing, speech and language, and/or developmental delay. If a mother, father, or other caregiver expresses concern over the child’s hearing, speech, language, or development, it is a risk factor for hearing loss. They may say things like: "I'm a little concerned about my child's hearing" or "I don't think my child is speaking yet and they really should be” or "My child seems to be a little clumsy" or "My child is not sitting up like my other children did at the same age” or "My child is not able to walk as well as I think he should." If there are concerns such as this, the child should have a hearing test. Hearing tests are non-invasive, they don’t hurt the child in any way, and they are inexpensive. There are accurate methods to assess a child’s hearing, no matter the age of the child. There are no risks associated with hearing testing so children should always be tested whenever there is caregiver concern about hearing, speech/language issues, or developmental delay.
Family history of permanent childhood hearing loss. If a parent or sibling has permanent childhood hearing loss, that is a risk factor for hearing loss. There are well over 100 genes associated with hearing loss. Hearing loss with a hereditary basis, that is, a genetic basis, is very common. In fact, genetic factors account for half of all hearing loss.
Newborn intensive care unit (NICU) stay of greater than 5 days; or ECMO (extra-corporeal membrane oxygenation); assisted ventilation; exposure to ototoxic medicines or loop diuretics; and hyperbilirubinemia (jaundice) requiring exchange transfusion. This is information that the caregiver will likely be able to provide. Was the child in the well-baby nursery or the NICU? Did they leave the hospital with the mother, or did they have to stay?
Perinatal infections, or infections in utero before the child was born. In these cases, the mother usually has this infection, and it gets transmitted to the child. Cytomegalovirus, or CMV, is one example. In many people, there may be no symptoms of CMV and it's not a problem, but in a newborn child, particularly if the child is premature, it can be very serious, and it can lead to permanent hearing loss. Some infections, such as rubella and measles, always cause hearing loss in infants. Other perinatal infections that are risk factors for hearing loss include herpes, syphilis, and toxoplasmosis.
Craniofacial anomalies, or abnormalities, including those involving the ear and ear canal. Perhaps the ear is not well-formed, or there are skin tags or pits near the ear; these conditions are associated with hearing loss. Temporal bone anomalies is also a risk factor. Any child with these issues should undergo a diagnostic hearing test.
Neurodegenerative disorders, e.g. Hunter syndrome, sensory-motor neuropathies (Friedreich ataxia, Charcot-Marie-Tooth syndrome).
Syndromes associated with hearing loss such as neurofibromatosis, osteopetrosis, Usher syndrome, and others including Waardenburg, Alport, Pendred, and Jervell and Lange-Nielsen. Physical findings associated with a syndrome known to include permanent hearing loss, such as a white forelock (associated with Waardenburgh syndrome), are a risk factor for hearing loss.
Culture positive post-natal infections associated with sensorineural hearing loss, e.g., confirmed bacterial and viral meningitis.
Head trauma requiring hospitalization, as head trauma can cause hearing loss.
Chemotherapy. Some chemotherapy drugs can cause hearing loss. This is one of the most common causes of hearing loss in children. A hearing loss caused by chemotherapy can progress over time, so children who have received chemotherapy should have repeated hearing tests over time to monitor the hearing loss.
At least 50% of congenital hearing loss is hereditary, so knowing the family history is important. Sometimes a referral to a geneticist for a genetic assessment is warranted. Approximately 30 to 40% of children with hearing loss have associated disabilities. Every child with hearing loss should be evaluated by a team of professionals: an audiologist; ear, nose, and throat physician; neurologist; and other professionals indicated such as an ophthalmologist. In addition, children with syndromes known to cause hearing loss should always receive a complete hearing assessment (or repeated assessments if there is a risk for a progressive or late-onset hearing loss).
Also, keep in mind that up to 50% of children with hearing loss at age 9 passed their newborn hearing screening. Newborn hearing screenings cannot detect hearing loss that begins later. As early childhood professionals, you may be the first person to suspect a child has hearing loss. Knowing these factors can help you to be more aware of which children are most at risk. With childhood hearing loss, the goal is to identify and treat it as soon as possible to minimize any impact on speech and language development, social-emotional development, and the child’s academic/educational experience.
This Ask the Expert is an edited excerpt from the course Identification and Diagnosis of Hearing Loss in Preschool Children: What the Early Childhood Educator Should Know About Hearing, Part 2, by James W. Hall III, PhD.
