What a joy to welcome a baby into the family! It is an event that is widely celebrated, anticipated around the world. Expecting parents spend months preparing for this arrival and are never prepared enough till the newborn arrives safe and healthy. How many pediatrcians or obsterecians discuss hearing screening and speech and hearing milestones with these parent? Lack of awareness and misconceptions around new born hearing loss have led to many children being diagnosed late. Parents are in denial and waste much of their vluable time in panic leading to delayed action. A delayed intervention can end up having long-term or life-long effects on overall developmnet of child's speech, language, academic,social abilities and overall quality of life.
In a study by Neuman et al, it was highlighted that 38% of the infants born in the world do not have access to any kind of hearing screening at birth.There are several reasons why this needs to a widespread awareness to new expecting parents, medical professionals and primary care workers. Hearing loss is one of the most common congenital anomalies, occurring in approximately 2-4 infants per 1000 and as many as 50% of infants born with hearing loss have no known risk factors.
Hearing begins in the womb: There are several embryological and fetal studies that suggest that baby starts hearing in the last trimester of pregnancy. Consistent responses to external sounds have been obtained around 28 weeks of pregnancy.
Hearing screening: Screening for hearing loss can be done as early as the day of birth. It involves a simple test called Oto-acoutsic emission(OAE) test which screens for good inner ear function. In addition an Automated Auditory Brainstem Response(AABR) may be be used to get a response from the hearing nerve using simple non invasive methods.
Diagnostic test for hearing loss: A diagnostic follow-up testing for infants not passing the screening is essential to confirm if an infant has a hearing loss. A confirmatory diagnostic ABR will be conducted to confirm the hearing loss, along with testing the middle ear status with suitable protocols for an infant. All the tests are non-invasive and can be done when the baby is in natural sleep. According to Juarez et al (2020), the current loss to follow-up rate in countries with proper hearing screening protocols is as high as 34.4%. Previous studies have found that lack of parental and primary care provider awareness of new born hearing screening results are significant contributors to loss to follow-up.
1-3-6 goals: The Joint Commsion on Infant Hearing 2019 position statement recommends that all infants are identified as early as possible, and appropriate intervention initiated, no later than 3–6 months of age. Intervention for congenital hearing loss as early as 3 to 6 months is critical. The baby's brain is using all the sensory inputs from eyes, touch, hearing, taste and smell to absorb all the experiences and form those neural connections or "templates" that last a lifetime. These experiences are the building blocks of language and communication. Weak access or no access to these "raw materials" lead to long lasting and irreversible changes in the growing brain.
To be continued
Part 2/5 Causes of hearing loss; type and degree of hearing loss in babies
References:
Neumann, K., Mathmann, P., Chadha, S., Euler, H. A., & White, K. R. (2022). Newborn Hearing Screening Benefits Children, but Global Disparities Persist. Journal of clinical medicine, 11(1), 271. https://doi.org/10.3390/jcm11010271
Juarez, Jose & Shaffer, Amber & Chi, David. (2020). Follow-up after failed newborn hearing screening: Parental and primary care provider awareness. American Journal of Otolaryngology. 41. 102614. 10.1016/j.amjoto.2020.102614. Assessed and Endorsed by the MedReport Medical Review Board