Screening of Hearing in Newborn Infants: Follow-Up and Outcome After 40 930 Births in Babol, Northern Iran

Background: The purpose of this study was to investigate the results of hearing screening in all newborn infants, and their follow-up in Babol, northern Iran. Methods: Between 2006 and 2014, all healthy neonates delivered in 3 hospitals were included in this cross-sectional study. Newborns were screened using the transient evoked otoacoustic emissions test before discharge. Those who failed to pass the examination were tested for auditory brainstem response (ABR) by the age of one month. The infants referred from the previous level underwent tests of auditory steady state response, ABR and impedance audiometry before the age of 3 months. For infants with the diagnosis of bilateral hearing impairment, it was recommended to use a hearing aid in 3 months. Then, their parents were recommended to take infants again to the hearing testing centers within next 6 months. If the infant’s hearing was not improved, he/she was advised to undergo cochlear implantation. Results: In total, 40930 newborns were screened. Out of them, 62 (1.5 per 1000 live births) were finally diagnosed to have hearing impairment, of whom 14 had unilateral and 48 had bilateral disorders (candidate for supportive measures). Overall, 986 (2.4%) were lost to follow-up and 11 (0.03%) died over the first 3 months of age. At the end of the 6-month follow-up for supportive stage, 15 out of 48 infants received a hearing aid and 18 (0.4 per 1000 children) underwent cochlear implant surgery. Fourteen out of 48 cases were lost to follow-up over supportive stage. Conclusion: It is recommended that all newborns undergo hearing screening test before hospital discharge, and those with impairment receive supportive measures from 3 months of age, and be re-examined at 12 months of age.