The pilot study of a nationwide neonatal hearing screening in Iran: Akbarabadi and Mirzakouchak- Khan hospitals in Tehran (June 2003-October 2004)

This study investigates the conditions under which neonatal hearing screening is useful in Iran. The objectives of the study were to identify prevalence of significant bilateral SNHL and then to demonstrate whether newborn mass screening is feasible and cost effective and would result in early detection and treatment of significant hearing impairment. Babies born at Akbarabadi and Mirzakouch-Khan university maternity hospitals from June 2003 to October 2004 were screened at birth in three stages by using transient evoked otoacoustic emissions (TEOAEs) and ABR. All newborns were tested under standard conditions before discharge from the hospital. According to the screening results, full audiological evaluations were performed when necessary. The screening method used was the TEOAEs-acoustic method. There were three stages in this study: initial screening, re-screening and diagnostic tests with ABR/OAEs. High risk neonates, especially those hospitalized in NICU, were scheduled for follow-up even if they were normal in the initial screening. The result from 8490 live newborns indicated that 89.7% of newborns proved normal in the primary screening in the maternity ward, and 10.3% were abnormal. Out of 873 infants scheduled for follow-up study only 571 neonates returned. Using follow- up letters and phone calls, we managed to improve the response rate to 56% of bilateral failures. Using Poison's distribution for frequency rate of hearing impairment and normal estimate for this distribution and 95% confidence intervals, significant bilateral sensorineural hearing loss was present in ~1 to 4 per 1000 live births in the well baby nursery population (12 neonates), and in ~2.5 to 4.6 per 100 infants in the intensive care unit. The outcome of this program has stimulated the development of a nationwide (universal) newborn screening program which will be started in near future. Mass newborn screening for hearing impairment in our population was found to be feasible, beneficial, cost beneficial and justified.