Hearing loss prevalence and risk factors among Iranian deaf children: The first report from Iran

Abstract

Background: There are many regional variations in the rate and predisposing factors of hearing loss and these could vary over time. The aim of this study was to describe the characteristics and possible etiology of severe to profound bilateral sensorineural hearing loss (SNHL) among Iranian children who were a candidate for cochlear implantation. Materials and Methods: We designed a cross-sectional study to evaluate children with profound SNHL referred to Baqiyatallah Cochlear Implantation Center from all over the country of Iran. Among 471 referred children, 310 cases with diagnosis of bilateral profound SNHL ranging in age from 6 months to 4 years between 2005 and 2011 were enrolled. Results: The mean (±standard deviation) age of individuals and the mean age of diagnosis was 3.50 ± 1.23 and 164 (53%) were male. Considerable risk factors for SNHL in 218 patients (70.3%) were obvious. A total of 103 (33%) children had one or more close relatives with deafness in their family, so they were considered to be hereditary deafness cases, followed by prematurity 32 (10.3%), syndromic etiology 25 (8%), maternal toxoplasmosis, rubella, cytomegalovirus, herpes infection 12 (3.9%), severe hyperbilirubinemia 9 (3%), eruptive infections 9 (3%), meningitis 8 (2.6%), asphyxia 6 (2%), and oto-toxic drug 6 (2%). Our data showed the prevalence of 65% consanguineous marriage among parents of deaf children. Conclusion: This is the first attempt to describe the risk factor of SNHL in Iran. Among the identifiable causes of severe to profound SNHL in Iranian population, the consanguineous marriage was the most common risk factor. Further analytical studies focusing on the relation between etiology and demographic factors were recommended.