Int. Adv. Otol. 2010; 6(3) 365-370

Study of prevalence and causes of hearing loss in high risk neonates admitted to neonatal ward and neonatal intensive care unit.
Shahin Abdollahi Fakhim, Masoud Naderpour, Nikzad Shahidi, Fazileh Basharhashemi, Nayyereh Nejati, Seddigeh Hoseinpour Sakha, Mahasti Alizadeh. Department of otolaryngology Head and Neck surgery, Tabriz university of Medical Sciences, Tabriz, Iran

Background and goals: Hearing loss in neonates is one of the most important problems in which any delay in early diagnosis and intervention will cause a great undesirable impact on speech, language and cognitive abilities. So it is always recommended that if there is significant prevalence of neonatal hearing loss, screening programs should perform at least on high risk population of neonates to detect cases actively.

Material and Methods: This is an analytic, cross-sectional study on 1823 low risk neonates and 876 high risk neonates admitted at " Koodakan, Alzahra, and Talegani "  hospitals during years 2004-2006. Method of sampling was simple randomized sampling.
In all neonates otoacoustic emission was performed and if it was abnormal second otoacoustic emission after two weeks of antibiotic therapy was done. Neonates with abnormal second otoacoustic emission underwent auditory brainstem response. Criteria for hearing loss was hearing threshold more than 30 dB in auditory brainstem response. Data was analyzed with SPSS version 14.

Results: Prevalence of sensori-neural hearing loss was 0.2 percents in low risk neonates and 4.2 percent in high risk neonates. Auditory brainstem response was abnormal Bilaterally in 62.2 percent and unilaterally in 37.8 percent.
Factors which had significant relationship with hearing loss include : Birth weight less than 1500 gram, Craniofacial abnormalities, meningitis, using of ototoxic drugs in neonates, mechanical ventilation more than five days, prematurity, familial history of hearing loss, hyperbilirubinemia requiring exchange transfusion.
Factors that didn't have statistically significant relation were intrauterine infections, using of ototoxic drugs in pregnancy, finding related to one of the syndromes accompanied with hearing loss, and APGAR score 0-4 at first minute and 0-6 at fifth minute.

Conclusion: Prevalence of sensori-neural hearing loss in high risk neonates was 4.2 percent in our study. This is twentyfold more than low risk neonates. Since early diagnosis and intervention will prevent significant complications and on the other hand the cost of screening tests is very low, it is important and logical from the point of health and economy that the screening tests should become necessary for all of neonates.