Incidence of hearing impairment in at risk babies

Abstract

Babies treated in neonatal intensive care are prone for hearing problems and with the decrease in infant mortality, babies who survive many perinatal risk factors are increasing. Deafness in 1st three years of life may impair the full development & maturation of auditory system & it is well known that deafness in infancy & childhood interferes with normal development of speech & language. To prevent this & to initiate rehabilitative procedure as early in life as possible a screening method to detect auditory disabilities in newborns is of great importance. Based on this background the present study determine to evaluate to know the incidence of hearing impairment in infants at risk.This is a prospective observational study conducted in JJM Medical College, Davanagere, Karnataka. A total 940 patients attended to JJM Medical College and Hospital and diagnosed with hearing impairment according to American Joint Committee statement on infant hearing screening (JCIH) criteria. All the patients under 2 years with history of high risk factors – pre–term, low birth weight, birth asphyxia, neonatal seizures, and hyperbilirubinemia were selected for the study. Those who failed in this test underwent repeated OAE after 6 weeks, followed by brain stem evoked response audiometry (BERA) if the second OAE was negative. Out of 940 high risk cases, 350 had profound hearing loss, 83 had severe hearing loss, 125 had moderate hearing impairment, 36 had mild hearing impairment &346 had normal hearing sensitivity. Out of 48 patients with normal hearing sensitivity, 53 patients were preterm, 166 had hyperbilirubinemia, 23 had neonatal convulsions, 68 birth asphyxia, 89 were of low birth weight. Out of 147 cases 31 patients had mild/moderate hearing impairment.Neonatal jaundice carries the highest risk of hearing impairment followed by birth asphyxia, neonatal convulsions and low birth weight.BERA is the tool which can confirm the normal sensitivity of hearing whenever required & is very useful in early detection of hearing loss and planning rehabilitative procedures.