T82. Neonatal brainstem audiometry is associated with language development

Abstract

Preterm birth increases the risk for abnormal neurodevelopment including delayed language development. Function of the auditory pathway in neonatal period may correlate with language outcome in childhood. Our objective was to study if neonatal brainstem auditory evoked potential (BAEP) and brainstem audiometry (BA) results in preterm babies are associated with receptive lexicon at one year corrected age. In this retrospective study, we included 155 preterm babies (birth weight ⩽1500 g and/or birth ⩽32 gestational weeks) born 2007–2012 in Turku University Hospital providing the following information: BAEP and BA recording results at the mean corrected age of 1.1 months (0.28 SD) and information on early receptive and expressive lexicon growth at the mean corrected age of 12.1 months (0.55 SD) gathered using the Finnish version of the MacArthur Communicative Development Inventory (CDI). CDI is a structured rating instrument where parents denote the words that their child understands but does not say (receptive lexicon) and the words they say (expressive lexicon). In this study, we used only the receptive lexicon. This was done because the expressive lexicon is very small at one year of the age. All children were from Finnish speaking families. In addition, we gathered information about possible covarying factors: gestational age at birth, birth weight, small for gestational age, gender, hearing loss, age at the time of BAEP recording and CDI completion. Infants with small receptive lexicon at one year corrected age had longer latency of component V (r = −0.17, p = 0.036), interpeak latencies (IPL) I-V (r = −0.21, p = 0.0087) and IPL III-V (r = −0.17, p = 0.040) in BAEP recording with right ear stimulation at one month corrected age. Other BAEP variables on either side did not show similar associations with CDI. BA thresholds did not show associations with CDI. The possible covarying factors in the analyses did not affect the receptive lexicon. Our study suggests that in preterm infants prolonged conduction in the auditory pathway from the dominant right ear is associated with small receptive lexicon size at the corrected age of one year. Several studies show right-ear advantage (REA) in processing speech stimuli already in neonatal period. According to our results, delayed auditory maturation in the right ear seems to have greater influence on language development compared to the left ear, supporting REA. In the future, this information might help us to improve the recognition of preterm babies at risk for delayed language development already at term age which might lead to better results in language rehabilitation.