Auditory brainstem response in very preterm, moderately preterm and late preterm infants

Background: Auditory brainstem response across preterm infants help in understanding difference if any in auditory maturation. Objective: To analyze and compare absolute and interpeak latencies of ABR in very preterm, moderate preterm and late preterm infants at term age. Method: ABR traces were obtained from 148 ears of preterm infants (52 of very preterm, 44 of moderately preterm & 52 of late preterm) at term age. ABR was recorded with 11.1/s clicks at different intensity levels. Results: Absolute latencies of peak I, III, V and interpeak latencies of peak I-V, I-III and III-V were analyzed and compared between three preterm groups. One way ANOVA was used to compare ABR parameters between three groups of preterm infants and also to compare ABR parameters across various gestation ages. There were no overall differences in absolute latencies, interpeak latencies and amplitude of ABR between preterm groups and across various gestation ages (P > 0.05). Pearson correlation was used to find the correlation between gestation age and ABR parameters. However, no correlation was found. ABRs were similar among preterm groups at term age which reflects that the brainstem maturation is similar among preterm groups. Conclusion: Gestational age at birth does not seem to influence absolute and interpeak latencies of ABR at term age. In preterm neonates, the findings lead to suggest that maturation of auditory pathway occurs in a similar manner in preterm infants regardless of gestational age at birth. We conclude that preterm birth alone as a risk factor does not appear to have any marked effect on the development of ABR at term age.