KY Chan, F Lee, CB Chow, CC Shek, R Mak

Abstract

From a cohort of 6,127 live births in Princess Margaret Hospital, 309 (5%) were identified as being at risk of hearing impairment. The at risk infants were screened at postconceptual age of 37 weeks or before age of 3 months when they were in stable condition by measuring the auditory brainstem response (ABR). Thirty-five (11%) of 309 at risk infants failed the ABR test. Twenty-six infants were further evaluated by ABR examination, distraction test and impedence test. Twelve were confirmed to have moderate to severe hearing loss. Their risk factors were as follows - 4 babies with Down syndrome, 2 with severe ear malformation, 1 preterm baby, 1 baby with severe asphyxia, 3 with severe neonatal jaundice with serum bilirubin of >= 340 μmol/L and 1 with elevated netromycin level. The overall rate of hearing impariment of at risk neonates was 3.8% and the incidence of moderate to severe deafness for the cohort was 1.9 per 1000 live births. Auditory training was provided to all severely hearing impaired infants before one year of age. Auditory brainstem response remains to be the best currently available method for early detection of hearing loss in at risk neonates.