Screening for Hearing Loss in High-Risk Neonates Using Otoacoustic Emissions

Abstract

Context: The development and maturation of the hearing process begin in the fetal stage and progresses up to 6 months of age. Neonatal screening is therefore an essential method to screen for hearing loss at an early age. As there is a paucity of literature on the use of otoacoustic emissions (OAEs) and brainstem evoked response (BERA) tests for screening, hence we conducted a prospective observational study to screen the high-risk neonates admitted to neonatal intensive care unit (NICU) using OAE and further BERA (wherever indicated). Aims: The primary objective was to estimate the incidence of hearing loss in high-risk neonates admitted to NICU using OAEs as a screening tool. A secondary objective was to determine the risk factors predictive of hearing impairment in these neonates. Settings and Design: It was a prospective observational study conducted in a tertiary care hospital. Subjects and Methods: The study was conducted over a period of 1 year from April 1, 2021, to March 31, 2022. Fifty neonates with high-risk factors who fulfilled the inclusion criteria were enrolled and subjected to a two-staged OAE screening test and further BERA (in neonates where overall OAE result was REFER). Statistical Analysis Used: Continuous data variables were presented as means and standard deviations. Categorical data were presented as percentages and Chi-square test was used to derive comparisons. For all statistical testing, P < 0.05 was considered statistically significant. Results: Of 50 neonates enrolled in the study, 22 (44%) passed the Stage I OAE. The remaining 28 (56%) underwent Stage II OAE, out of which 17 (34%) passed the Stage II screening. Eleven neonates with overall OAE results as REFER were taken up for BERA. Three neonates (6%) had a hearing loss on BERA while in 8 (16%) BERA was normal. The overall incidence of hearing loss was 6%. The variables with a statistically significant correlation with the results of OAE were - APGAR score and perinatal asphyxia at a low APGAR score. Conclusions: The incidence of hearing loss in this study was 6%. APGAR score and perinatal asphyxia at a low APGAR score at 1 and 5 min had statistically significant correlation with the outcomes of OAE screening.