Low prevalence of hearing impairment among very low birthweight infants as detected by universal neonatal hearing screening.
OBJECTIVE
To (a) study the prevalence of hearing impairment in a cohort of very low birthweight (VLBW) infants and (b) evaluate the effectiveness of transient evoked otoacoustic emissions (TEOAE) as a first stage in-hospital hearing screening tool in this population.


METHODS
The study group was a cohort of 346 VLBW infants born in 1998-2000 at The Sheba Medical Center. The prevalence of hearing impairment in the study group was compared with that of all other newborn infants participating in a universal newborn hearing screening programme during the same period. To evaluate the effectiveness of TEOAE, a control group of 1205 healthy newborns who had no known risk factors for hearing impairment was selected. The results and follow up of hearing screening for these infants were examined retrospectively.


RESULTS
Only one VLBW infant (0.3%) was diagnosed with bilateral sensory-neural hearing loss. In addition, nine infants (2.7%) were diagnosed with conductive hearing loss. Bronchopulmonary dysplasia and low Apgar score were the most significant factors for predicting the occurrence of conductive hearing loss. The percentage of VLBW infants who successfully passed the in-hospital TEOAE screening was 87.2, compared with 92.2% in the full term control group. No false negative cases were detected on follow up.


CONCLUSIONS
The study shows a low incidence of sensory-neural hearing loss in a cohort of VLBW infants and a relatively high incidence of conductive hearing loss. TEOAE screening was found to be an effective first stage in-hospital hearing screening tool in this population.
Speech and Hearing Center, The Chaim Sheba Medical Center, Tel Hashomer, Israel 52621. rothd@post.tau.ac.il
D
D
Ari-Even Roth
M
M
Hildesheimer
A
A
Maayan-Metzger
C
C
Muchnik
A
A
Hamburger
R
R
Mazkeret
J
J
Kuint
D001034:Apgar Score; D001997:Bronchopulmonary Dysplasia / Q000150:complications; D004812:Epidemiologic Methods; D016057:Evoked Potentials, Auditory, Brain Stem; D005260:Female; D034381:Hearing Loss / Q000175:diagnosis* / Q000209:etiology; D006314:Hearing Loss, Conductive / Q000175:diagnosis / Q000209:etiology; D006319:Hearing Loss, Sensorineural / Q000175:diagnosis / Q000209:etiology; D006320:Hearing Tests / Q000379:methods; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D007235:Infant, Premature, Diseases / Q000175:diagnosis* / Q000209:etiology; D019102:Infant, Very Low Birth Weight; D008297:Male; D015997:Neonatal Screening / Q000379:methods*; D017084:Otoacoustic Emissions, Spontaneous