Otoacoutic Emission Testing in Preterm and Term Sick Newborns: A Comparative Analysis

In newborns, both term and preterm, cochlear hearing loss is common due to different pathologies. Currently accepted methods for hearing screening in newborns are otoacoustic emission (OAE) and auditory brainstem responses. Among these two, OAE is quicker, economical and more accessible. In the present study we assessed OAEs in sick newborns, both term and preterm, having different pathological conditions. This descriptive study was conducted over 3 months in sick newborn care unit (SNCU) in a tertiary care hospital. All sick newborns admitted to SNCU in the study period were tested for otoacoustic emission. The results were subjected to the Chi square test (test of independence). Among 640 sick newborns, 184 were preterm; the rest being term newborns. Among the term sick newborns, 4.8% of those with birth asphyxia, 8.6% of those having septicaemia, 25% of those with hyperbilirubinemia needing exchange transfusion, 22.9% of those having meningitis and 33.3% of those with major congenital anomalies, had "refer" on OAE. Among preterm sick newborns, 30.8% of those with birth asphyxia, 32.5% of those having septicaemia, 75% of those with hyperbilirubinemia needing exchange transfusion, 41.7% of those having meningitis, 40% of those with major congenital anomalies and 8.7% of those with no co-morbidity had "refer" on OAE. Upon computing the p value of Chi square test performed on the results, the results were not significant (p = 0.85). Hence we didn't find any statistically significant difference between term and preterm sick newborns on OAE. The incidence of "refer" result in OAE increases with co-morbidities in both term and preterm sick newborns, somewhat more in preterm newborns. But preterm sick newborns do not seem to have an increased incidence of hearing impairment.