Audiologic assessment of extremely low birth weight infants: a preliminary report
Doyle, L.W.; Keir, E.; Kitchen, W.H.; Ford, G.W.; Rickards, A.L.; Kelly, E.A.
Pediatrics 90(5): 744-749
1992
ISSN/ISBN: 0031-4005 PMID: 1408548 Document Number: 403087
The aim of this study was to assess all relevant aspects of auditory function, including acuity and perception, of a cohort of extremely low birth weight ( lt 1000 g) children who survived to 8 years of age; 42 of the 59 consecutive survivors born over a 4-year period from January 1, 1977, had a full auditory assessment. Of the 42 children, 4 (9.5%) had a sensorineural hearing impairment, 5 (11.9%) had conductive hearing impairment, 24 (57.1%) had figure/ground differentiation problems, and 20 (47.6%) had a short-term auditory memory problem. The 4 children with sensorineural hearing impairments had had significantly higher maximum concentrations of bilirubin in the newborn period (median 167 mu-mol/L vs 138 mu-mol/L) and had required more intensive care; at 8 years of age they were significantly disadvantaged in verbal ability. The 5 children with conductive hearing impairments were not significantly different on any perinatal or other 8-year outcome variables. The proportion with figure/ground differentiation problems (57.1%) was significantly higher than in a normative population (11.7%, chi-2 = 24.2). Extremely low birth weight children with figure/ground differentiation problems were more likely to be restless in the classroom (45.0% (9/20)) than those without these problems (16.7% (2/12)), but the difference was not statistically significant (chi-2 = 2.7). Children with short-term auditory memory problems had significantly higher maximum bilirubin concentrations in the newborn period (median 152 mu-mol/L vs 137.5 mu-mol/L). At 8 years of age they had significantly reduced intelligence and reading ability. Even though the cohort is small, there is sufficient evidence that audiologic assessment of extremely low birth weight children should extend beyond just threshold measures of hearing acuity.