Hearing impairment in preterm very low birthweight babies detected at term by brainstem auditory evoked responses

Abstract

Seventy preterm babies who were born with a birthweight <1500 g were studied with brainstem auditory evoked responses (BAER) at 37‐42 wk of postconceptional age. The data were compared with those of normal term neonates to determine the prevalence of hearing impairment in preterm very low birthweight (VLBW) babies when they reached term. The BAER was recorded with click stimuli at 21 s−1. Wave I and V latencies increased significantly (ANOVA p < 0.01 and 0.001). I‐V and III‐V intervals also increased significantly (p < 0.05 and 0.001). Wave V amplitude and V/I amplitude ratio did not differ significantly from those in the normal term controls. Ten of the 70 VLBW babies had a significant elevation in BAER threshold (>30 dB normal hearing level). Eleven had an increase in I‐V interval (>2.5 SD above the mean in the normal controls) and one had a decrease in V/I amplitude ratio (<0.45). These results suggest that 14% (10/70) of the VLBW babies had a peripheral hearing impairment and 17% (12/70) a central impairment. Three babies had both an increase in I‐V interval and an elevation in BAER threshold, suggesting that 4% (3/70) had both peripheral and central impairments. Thus, the total prevalence of hearing impairment was 27% (19/70). Conclusion: About one in four preterm VLBW babies has peripheral and/or central hearing impairment at term. VLBW and its associated unfavourable perinatal factors predispose the babies to hearing impairment.

Low prevalence of hearing impairment among very low birthweight infants as detected by universal neonatal hearing screening

“…45 In our cohort, 1.5% of the VLBW infants were found to have abnormal ABR results-that is, prolonged BTT-despite normal ABR thresholds and normal TEOAEs. Similar findings were reported by Jiang et al 46 This finding supports routine implementation of TEOAE as a quick, easily performed first stage screening tool before discharge from What is already known on this topic N VLBW infants are at increased risk of sensory-neural hearing loss What this study adds N This study shows a low prevalence of sensory-neural hearing loss in a group of VLBW infants, which needs confirmation N The rate of conductive hearing impairment was high as expected hospital (thus reaching all babies), but a diagnostic ABR should also be routinely performed in this population.…”

Incidence and clinical value of prolonged I–V interval in NICU infants after failing neonatal hearing screening

“…Jiang et al [7] found an incidence of abnormal central ABR component in 17% of preterm very low birth weight infants. Although the populations differ with respect to birth weight and failing neonatal hearing screening, the prevalence of prolonged I–V interval as a measure of abnormal central component concur.…”

“…It is reported to be increased in preterm infants as compared to term infants [7–9]. The I–V interval shows an age-dependent decline up to about 2 years of age [10–12].…”

Two-year outcomes from very low birthweight infants in a geographically defined population across 10 years, 1993-2002: comparing 1993-1997 with 1998-2002

“…This was seen with both sensory neuronal and conductive deafness and the numbers of infants with deafness not corrected with aids increased from two to five. Recent studies have shown that there has been a decrease in sensory neuronal deafness in neonatal intensive care unit graduates overall 25. Studies of VLBW infants, however, continue to show a higher incidence of hearing impairments which are probably multifactorial in origin.…”