Brainstem evoked auditory response in preterm and full-term infants

Abstract

Background: The survival of preterm infants has increased substantially over last few decades because of improvements in obstetric and neonatal care. However, the newborn experience many perinatal complications including peripheral or central hearing loss. The prevalence of hearing loss is reported to be 1.5–6 per 1000 newborn in the well-baby nursery population. Brainstem evoked response audiometry (BERA) is a simple, noninvasive way of evaluating the hearing function and has been widely used for early detection of hypoacusis and neural conduction irregularities in the auditory pathway. Several risk factors associated with hearing loss during early infancy, such as hereditary cause, in utero infection, prematurity, asphyxia, hyperbilirubinemia, and ototoxic medications, have been described by the Joint Committee on Infant Hearing. Aims & Objective: To analyze and compare BERA responses in preterm and term infants. Materials and Methods: The infants (30 preterm and 30 term) attending Pediatric OPD of Bapuji Hospital and Chigateri General Hospital satisfying the inclusion criteria were subjected to BERA. Parameters such as absolute latencies of waves I, III, and V, and interpeak latencies (IPLs) I–III, I–V, and III–V were assessed and analyzed by using unpaired t-test. Results: Preterm babies had highly significant increased wave V threshold than controls. Waves III and V were delayed in preterm babies, IPLs of wave III–V were increased in the preterm group, and statistically significant increase was observed in IPL of wave I–V. Conclusion: This study indicates that preterm infants have prolonged latency of wave V, which reflects immaturity of the auditory system. Therefore, it is essential to screen all preterm infants at the earliest to prevent adverse effect on the developing auditory pathway.