Prospective Evaluation of Hearing Status in Neonatal Hyperbilirubinemia

Akshay Padinharakandy1, Balakrishnan Ramaswamy1, Devaraja K1

  • 1Department of Otorhinolaryngology, Kasturba Medical College, Manipal Academy of Higher Education, Manipal, Karnataka 576104 India.

Insights

Neonatal hyperbilirubinemia may not significantly impact hearing, as initial auditory screening failures often resolve. Further research is needed to fully understand transient effects on infant hearing.

Area of Science:

  • Neonatal Auditory Health
  • Bilirubin Metabolism
  • Neuro-otology

Background:

  • Hyperbilirubinemia is common in newborns, yet its effects on the auditory system are not well-documented.
  • Understanding potential hearing impairment in neonates with elevated bilirubin is crucial for early intervention.

Purpose of the Study:

  • To investigate the prevalence of hearing impairment in neonates with hyperbilirubinemia.
  • To assess the reversibility of hearing impairment in affected neonates through follow-up evaluations.

Main Methods:

  • A prospective case-control study comparing neonates with total bilirubin levels >15 mg/dl (cases) to those <15 mg/dl (controls).
  • Exclusion criteria targeted confounding factors like hypoxia, infections, and genetic predispositions.
  • Otoacoustic emission (OAE) testing at birth, with follow-up Brainstem Evoked Response Audiometry (BERA) at 2 and 6 months for abnormal OAE results.

Main Results:

  • 3 out of 57 cases failed initial OAE but showed normal BERA at 2 months.
  • 5 out of 60 controls failed OAE; 3 had normal BERA, and 2 were lost to follow-up.
  • No statistically significant difference in hearing impairment was found between hyperbilirubinemia and control groups.

Conclusions:

  • Elevated bilirubin levels, in the absence of other risk factors, may not cause significant, lasting hearing impairment in neonates.
  • Transient auditory changes observed in screening may revert with age, suggesting potential reversibility.
  • While not statistically significant, a trend nearing significance warrants further investigation into bilirubin's subtle auditory effects.