The Relationship between Severe Hyperbilirubinemia and Abnormal Auditory Brainstem Response (ABR) in Children

Introduction: hyperbilirubinemia is one of the most common cause of congenital sensory neuronal hearing loss. these patients are screened by auditory brainstem response (abr) test at bilirubin levels higher than 1% of gestational weight. aim of this study is to determine whether hyperbilirubinemia less than 1% of gestational weight could induce hearing loss and abnormal auditory brainstem response (abr).materials and methods:in this case control study the outcome of abr test in children younger than 3 years old with a history of term delivery and hyperbilirubinemia (bilirubin level less than 1% of gestational weight) were compared with the control group without hyperbilirubinemia matched for age and gender.results: mean abr amplitude (wave i, v) were significantly prolonged in neonates with jaundice compared with controls (p < 0.01). based on receiver-operating characteristic curves, a bilirubin level of 0.6% of gestational weight was the best discriminator with a sensitivity and specificity of 100%. in logistic regression analysis the relative risk of having an abnormal abr in bilirubin level > 0.6% gestational weight was 2.25 with 95% confidence intervals (ci) (1.44-3.89 and p=0.02).conclusion: our study showed a relevant association between bilirubin levels less than 20 mg/dl and abnormal abr.