The Hearing Status of Preterm Infant's ≤ 34 Weeks as Revealed by Otoacoustic Emissions (OAE) Screening and Diagnostic Brainstem Evoked Response Audiometry (BERA): A Tertiary Center Experience.

Abstract

To know the prevalence of hearing loss in preterm infants & to evaluate the sensitivity & specificity of otoacoustic emission (OAE) in detecting hearing loss in preterm infants ≤ 34weeks. A total of 70 preterm babies from 28 to 34weeks of gestational age were enrolled in the study. Detailed prenatal, perinatal, postnatal & family history and physical examination of the babies were carried out. First OAE was done at discharge or two weeks after birth, whichever was earlier and the second OAE assessment was done at 36-40weeks of corrected age. Diagnostic brainstem evoked response audiometry (BERA) was done in all infants at 36-40weeks of corrected age, at the time of second OAE. Neonates with hearing impairment were advised for early hearing aid amplification and were referred to the rehabilitation center for further management. The sensorineural hearing loss (SNHL) in either one of the ears was identified in 13 (18.57%) preterm babies. Bilateral profound SNHL was found in 5 (7.14%) babies. Auditory neuropathy profile was found in 7 (53.8%) out of 13 babies who had hearing loss. The sensitivity, specificity, positive and negative predictive values of second TEOAE compared with diagnostic BERA was 46.15%, 85.96%, 42.85%, and 87.5% respectively. Neonatal jaundice (p = 0.009) and history of exchange transfusion (p = 0.019) were found to be significant risk factors of hearing loss in our study. Other risk factors like mode of delivery, birth asphyxia, low APGAR score, meningitis, ototoxic drugs, and seizures were not associated with hearing loss. The prevalence of hearing loss in preterm infants < 34weeks is very high. OAE alone is not an ideal screening test for high-risk neonates ≤ 34weeks because of its low sensitivity. OAE combined with diagnostic BERA should be done in all high-risk infants preterm neonates ≤ 34weeks to identify cases of auditory neuropathy spectrum disorders.