Newborn hearing screening in a single private Japanese obstetric hospital

Background: Hearing loss is one of the most common abnormalities present at birth. The authors examined the frequency of newborn hearing disturbance at a single obstetric hospital to exclude technical varieties or varieties of subjects which are inevitable in multiple institutional cooperative studies. Methods: The newborns were examined with an automated auditory brainstem response screener, the ALGO 2e, on day 4 post-partum. This Screener uses 35 dB near hearing level click stimuli and provides a PASS/REFER result that requires no interpretation. The PASS result is accepted as adequate evidence of hearing and REFER result as required further diagnostic testing to determine hearing status. Screenings of REFER outcomes were repeated at 1 month of age. Comparisons were made of the results and the Japanese multiple institutional trials by Mann-Whitney U-test. Results: The authors screened 8979 out of 13 494 neonates born from July 1999 to October 2004. The neonates with unilateral or bilateral REFER outcomes were 37 cases (0.41% of the total examined) on day 4, and 31 cases (0.35%) at 1 month of age. Five of the 31 neonates had PASS outcomes at 6 months of age. Among the 31 REFER neonates, eight (25.8%) had otolaryngeal complications. Conclusions: In the present study, screening results at 1 month of age resembled the final diagnosis obtained at 6 months of age; out of 31 REFER cases, 26 cases were diagnosed with hearing loss. In contrast, in the multiple institutional study, both unilateral and bilateral REFER rates were much higher than the rates of final hearing loss. Concerning the final diagnoses of bilateral hearing loss, the authors' results (0.10%) and the multiple institutional studies' results (0.05% in low-risk and 2.19% in high-risk neonates) were comparable to the results reported in the USA. To expand the newborn hearing screening program, it is crucial that authority and institutions concerned promote the development of a national or prefecture-based early hearing loss identification and intervention network.