Newborn hearing screening on infants at risk

Abstract

Objectives: This article presents the results of newborn hearing screenings on infants at risk of hearing impairment at the French University Hospital of Besançon from 2001 to 2007.

Materials and methods: All newborns at risk of hearing impairment were tested according to the method recommended by the Joint Committee on Infant Hearing (JCIH): a two-step automated oto-acoustic emissions (AOAE) program, completed by an auditory brainstem response (ABR) for the positive diagnosis of hearing impairment. The screening started with AOAE on the third day of life, at the earliest. If one or both ears did not have AOAE, the infant was re-tested at which time, should the AOAE again be positive, ABR was performed. When the ABR threshold was 40dB or more, the infant was referred to an audiologist specialized in infant deafness for diagnosis confirmation and management.

Results: Over the period, 1461 infants were screened, among whom 4.55% were diagnosed as deaf or hard of hearing. Nearly 10% of the infants were lost to follow up. Forty-six children had a sensorineural hearing impairment, of which 34 were bilateral and were managed before the age of 6 months. The risk factors for sensorineural hearing loss were (in order of statistical significance): severe birth asphyxia; neurological disorder; syndromes known to be associated with hearing loss; TORCH (toxoplasmosis, rubella, cytomegalovirus, herpes) infections; family history of deafness; age at the time of screening; and the association of 2 or more risk factors. However, birth weight inferior to 1500g and premature birth before the 34th week of pregnancy did not show a statistically significant influence on sensorineural hearing loss. Craniofacial anomalies (mostly cleft palate and ear aplasia) were a significant factor for conductive hearing loss.

Conclusion: Our selected hearing screening on infants at risk allowed 60 deaf children access to early management. However, too many children were lost to follow up; which revealed that better information regarding risk of hearing loss must be provided to parents and paramedics and universal newborn screening needs to be performed. The most important result of this study is that in a population of hearing impaired children, with an impairment incidence close to what is commonly reported, the association of several risk factors proves to be a significant additional risk factor for hearing impairment.