Birth weight and the risk of childhood hearing impairment

 Abstract  Background: Low birth weight neonates are confronted with some problems after  birth, they should be followed up and evaluated at different ages of life.The aim of this study was to determine the impact of birth weight on the risk of sensorineural hearing impairment on children.  Method: This cross sectional and retrospective study determined the prevalence  of hearing problems in low birth weight and normal birth weight school age children.  The sample was consisted of 2400 children who referred to special educational organization for hearing screening before entrance to school in Mashhad - Iran between  June 2005 and June 2006. Hearing problems were checked in all groups. Case definition was based on the mean sensorineural hearing loss of more than 35 decibel (dB) hearing level (HL) and in the better-hearing ear averaged over the pure-tone hearing thresholds at 500, 1000, 2000 and 4000 Htz. The results were then compared the low birth weight and normal birth weight children.  Result: This study showed that prevalence of hearing problems was 1.4%. The  prevalence of hearing impairment in low birth weight (LBW) was 2.1% and 1.3% in  normal birth weight (NBW). There wasn't significant difference in hearing impairment  between two groups (p=0.255).  Conclussion: In this study there was no significant difference between low birth  weight and normal birth weight children in hearing impairment although other studies  indicated that the risks of hearing impairment increase with the LBW and low  gestational age neonates. More investigation is needed for detecting the subtle hearing  problems in children.