Estimation of the Risk of Hearing Loss in Neonates with Hyperbilirubinemia in the Mysuru District Using Double Stage Double Screening Method

The study aimed to assess the risk of hearing loss in full-term neonates with hyperbilirubinemia, examining the relationship between bilirubin levels, onset age of hyperbilirubinemia, and hearing impairment. Additionally, it investigated whether hearing loss was transient or late-onset, using a cost-effective double-screening method. The study included 160 full-term neonates aged 0-1 month. Following completion of phototherapy for hyperbilirubinemia, all infants underwent initial screening with otoacoustic emissions (OAEs) and automated auditory brainstem responses (AABR). A second screening was administered to all infants within one month. Infants referred during the second screening, regardless of their first screening results, underwent diagnostic evaluation. For analysis, the infants were categorised into 4 groups, based on their bilirubin levels and onset of jaundice. After the initial screening, 37% of infants were referred, which decreased to 9% after subsequent screening, suggesting transient hearing loss in 76% of initially referred infants. Permanent hearing impairment was confirmed in 2.5% of infants following diagnostic evaluation, with 3 infants diagnosed with ANSD and 1 infant with sensorineural hearing loss, all from categories characterized by elevated bilirubin levels. The findings indicated that even bilirubin levels as low as 12 to 15 mg/dl could lead to hearing loss, particularly when jaundice onset occurred early. This study highlights the effectiveness of double-screening for identifying transient hearing losses in infants with hyperbilirubinemia, minimizing the need for diagnostic referrals. It underscores the importance of considering both bilirubin levels and onset timing to assess auditory risk fully.