Hearing loss in newborns

The Quebec newborn hearing screening program aims to detect hearing loss that is present at birth early on, and then to begin the treatment and rehabilitation needed before the age of 6 months. Newborn hearing screening tests have been in place in Quebec since 2021, in most regions, with a gradual rollout.

Hearing loss statistics in newborns

According to public health data, 4 to 6 babies out of every 1,000 births will have a hearing-related problem. In Quebec, one baby in 1,000 is thought to have permanent hearing loss, and 90% of the cases identified with a hearing disorder are thought to have no family history.

Because hearing disorders cannot be spotted with the naked eye at birth and are hard to pick up at a very young age, it is essential that screening be done systematically for all newborns, including those who are healthy and have no risk factors.

The types of hearing loss

There are different types of hearing loss. The greater the hearing disorder, the greater the possible impact on your baby's development.

• Neonatal hearing loss: hearing loss present at birth.
• Sensorineural hearing loss: it can affect the auditory nerve, the inner ear and how it works, or even the brain itself, in the part that interprets hearing, called the auditory cortex.
• Conductive hearing loss: this is a conduction problem in the middle and outer ear that keeps sounds from following their expected path.
• Mixed hearing loss: it combines different problems in the auditory system.

Why screen for hearing loss?

The answer is simple: the sooner hearing loss is known, the sooner we can step in and keep the negative effects on the child's overall development to a minimum.

Children identified with a hearing problem benefit greatly from quickly receiving the care and services suited to their situation, to protect their quality of life.

Under the protocol that governs the program, the goal is for newborns to be tested before the age of 1 month, always using corrected age if the child was born preterm, in an outpatient clinic. The test can also be done during the stay in the maternity ward, taking care to wait at least 24 hours after birth. Before that, fluid and debris may still be present in the child's ear canals and skew the results.

Screening is always done with the free and informed consent of the parents. A form has to be signed, after receiving the information about the program, to authorize screening.

The available tests

The program recommends two specific tests that can be used as a first step.

• The otoacoustic emissions test, also known by the acronym EOA-A. For a baby born at term, healthy and with no apparent risk factor, this is the first test performed, on both ears. If the result is conclusive, all is well and screening ends there. If the result remains incomplete, the same test is repeated as a second attempt after a short interval. If the results remain abnormal or uncertain, the next test is then used.
• The automated auditory brainstem response test, also called Peatc-A. It is usually used for a baby born at term, healthy and with no risk factor, whose results on the otoacoustic emissions test remain doubtful or incomplete. Being more specific, it makes it possible to reach a diagnosis.

Both tests send brief, regular, low-intensity sound stimulations through an earphone placed directly in the baby's ear canal; the physiological responses are then recorded. They are painless and carry no risk at all for your baby, and they are done while they are asleep and calm.

Babies with risk factors

For a newborn who has risk factors for hearing loss, the program provides for a different procedure: the Peatc-A test is prescribed right away.

• If the results are good: because of the risk factors, the child is still monitored for a few months, usually by an audiologist, with a few follow-up tests during the first year of life (most often at around 8 and 10 months).
• If the results are inconclusive: a second Peatc-A test is requested. If this second test is still inconclusive, a referral is made to a specialist to confirm the diagnosis, and follow-up is put in place according to the problem identified.

Risk factors for hearing loss in newborns

Even though the program is meant for all newborns, some of them are at higher risk of hearing disorders and hearing loss. Here are a few of them:

• certain infections contracted by the mother-to-be during pregnancy, such as toxoplasmosis, rubella and cytomegalovirus (CMV); these infections can be passed to the baby in utero and cause damage to the hearing centre or malformations of the auditory system;
• certain infections contracted by the baby in the neonatal period, such as meningitis;
• very preterm or extremely preterm birth, with a stay in intensive care: these babies can be at higher risk because of how immature they are;
• a family history of hearing loss;
• a syndrome that can have repercussions on hearing.

Newborn hearing screening can change the life of a baby with a hearing problem. Knowing a baby's hearing status early allows the health system to take charge very quickly.

If you have questions about your family history, or anything that worries you about a possible hearing problem in your baby to come, do not hesitate to ask your doctor to assess the situation with you.