Short-term outcomes of infants with hyperbilirubinemia-associated auditory neuropathy spectrum disorder in neonatal intensive care unit

Objectives: Hyperbilirubinemia is a high-risk factor for auditory neuropathy spectrum disorder (ANSD) as well as hearing loss in general. This study described the outcomes of hyperbilirubinemia-associated ANSD infants diagnosed in hearing screening in the neonatal intensive care unit (NICU).Methods: A total of 578 children with hyperbilirubinemia admitted to the NICU between October 2020 and October 2021 were included in this study. The distortion product otoacoustic emission (DPOAE) and automatic auditory brainstem response (AABR) were combined for hearing screening, and those who failed the DPOAE or/ and AABR underwent an auditory brainstem response (ABR) test. Infants with ANSD were followed up for 12 months.Results: Forty infants (40/578, 6.9%) failed the DPOAE or/and AABR tests, of which, 13 (13/578, 2.2%) were diagnosed as ANSD, and 27 (27/578, 4.7%) were diagnosed as having sensorineural hearing loss (SNHL). Of the 13 ANSD infants followed up for 12 months, 7 recovered, 3 improved, 3 did not recover, and 1 was lost, equating to improved or recovered hearing in 75% (9/12) of ANSD infants at 12 months of age. Moreover, the maximum bilirubin in recovered or improved ANSD infants was 408.6 +/- 129.0 mu mol/L, while the maximum bilirubin in unrecovered ANSD infants was 749.3 +/- 323.0 mu mol/L. Furthermore, poorly differentiated and absent ABR waveforms were observed in 6 and 14 ears at 1 month, 2 ears were lost, 6 (6/6, 100.0%) and 6 (6/12, 50.0%) ears were recovered or improved at 12 months of age.Conclusion: s: The incidence of hyperbilirubinemia associated-ANSD was 2.2% of infants screened in the NICU. ANSD caused by hyperbilirubinemia may be transient, with most infants improving or recovering hearing by 12 months of age. Infants with poorly differentiated ABR waveforms and low bilirubin concentration are more likely to recover and hearing aids are not recommended in hyperbilirubinemia-associated ANSD below 12 months of age.