Maturation of auditory brainstem response in early term infants at 6 weeks and 9 months

Abstract

BackgroundEmerging evidence indicates that infants who were born between 37 and 38 weeks of gestation are at higher risk of adverse long-term neurodevelopmental outcomes. Yet little is known about the auditory neural maturation during the first year of their life. AimTo compare the development of auditory brainstem response in early term (ET, 37–38 weeks gestational age, GA) and full term (FT, 39–41 weeks GA) infants. Methods126 infants received ABR testing at 6 weeks. 107 of them returned for the second assessment at 9 months, among which, 93 completed the ABR recordings. Comparison of the ABR variables were made depending on gestational age. ResultsAnalysis of covariance (ANCOVA) was used to identify the differences in ABR outcomes between two groups. After controlling for confounders, latencies for wave III, V and I-III, III-V and I-V intervals were prolonged in ET group compared with FT group at 6 weeks (all p<0.03). ABR parameters of both groups developed as the infants got older. At 9 months, ET infants remain showing the longer wave V latency and I-V interval (all p < 0.02) than FT infants. ConclusionDuring early postnatal life, ET has a different pattern of functional auditory brainstem development comparing with FT infants. The prolonged auditory conduction time suggests less mature of the central auditory system in ET infants before 9 months.