A hearing screening in very low birth weight preterm infants by auditory brainstem response

Background: ABR has been used as an objective, non-invasive tool to screen neonatal deafness. In this article, we evaluated the prevalence of deafness in VLBW preterm newborns by ABR, and attempted to search for a suitable failed/passed criterion. Methods: ABR screening test was performed in 88 VLBW preterm newborns. The infants whose threshold was ≤ 35dB nHL were classified as 'Group A'; those whose threshold was ≤ 25dB nHL were classified as 'Group B'. All of the newborns of either Group A or Group B received the successive ABR screening test and behavioral audiometry to confirm whether they have hearing impairment or not. Results: Fourteen newborns (16%) were included in Group A and 19 newborns (22%) in Group B. There were five newborns who belonged to Group B, but not to Group A; all of them were found to have normal hearing in the successive test. Eight newborns (9%) were defined to have hearing impairment finally, they all belonged to both Group A and Group B. Incidence of deafness in Group A is 57%; however, 42% in Group B. The predictive value of deafness in Group A was better than that in Group B. Conclusions: The prevalence of deafness in VLBW newborns was 9%. ABR is a tool with high sensitivity and predictive rate in neonatal hearing screening. Threshold ≤ 35dB nHL is preferable criterion for ABR Screening. We recommend that all of the newborns who were considered to have risk factors of deafness should be referred for ABR testing in order to lower the average age of diagnosis.