The results of newborn hearing screening by means of transient evoked otoacoustic emissions.
OBJECTIVE
The incidence of sensorineural hearing loss is between 1 and 3 per 1000 in healthy neonates and 2-4 per 100 in high-risk children. Transient evoked otoacoustic emissions (TEOAEs) represent a method which can be applied to all newborns prior to hospital discharge, enabling early identification of hearing loss. The aim of the study was to evaluate the results of newborn hearing screening by means of TEOAEs.


METHODS
Between 01.10.2002 and 30.09.2003, 5601 newborns born in the University Hospital in Poznan, Poland were screened with ERO SCAN (MAICO). Healthy neonates were screened in the second or third day of life and children treated in pathology unit--when their general condition was stable. The risk factors of hearing loss were recorded in a questionnaire. Children who failed the screening test or had risk factors of hearing impairment were referred to the outpatient clinic for further evaluation.


RESULTS
Risk factors were identified in 739 newborns. The most often risk factors were: use of ototoxic drugs, low Apgar score and prematurity. Positive test result was obtained in 219 (3.91%) children unilaterally and in 137 (2.45%) bilaterally. In healthy children the prevalence of positive results was 3.56% and in high-risk infants 24.9%. The relative risk of positive test results was the highest in infants with positive family history (RR=7.5), congenital malformations (RR=6.7) and low Apgar score (RR=5). Of the group of 912 children, who were referred to the specialist, only 218 turned up to be assessed during the observation period and had the additional otoacoustic emission test performed. There was not any significant difference in the percentage of children with and without risk factors who turned up for the second test and in whom the result was positive (39.7% versus 40.3%). In 41.9% children with risk factors whose screening test was negative, the second exam gave positive result.


CONCLUSIONS
The incidence of positive results in newborn hearing screening is much higher than the prevalence of hearing loss in general population and these results need verification by more precise methods. However, TEOAEs enable to select children who should be referred for audiological evaluation.
Wroblewska-Seniuk
Katarzyna
K
Chair of Neonatology, Poznan University of Medical Sciences, ul. Polna 33, 60-535 Poznan, Poland. kwroblewska@post.pl
Chojnacka
Karolina
K
Pucher
Beata
B
Szczapa
Jerzy
J
Gadzinowski
Janusz
J
Grzegorowski
Michal
M
D000161:Acoustic Stimulation; D001300:Audiometry, Evoked Response; D034381:Hearing Loss / Q000175:diagnosis* / Q000453:epidemiology; D006801:Humans; D007231:Infant, Newborn; D015997:Neonatal Screening / Q000379:methods*; D017084:Otoacoustic Emissions, Spontaneous; D011044:Poland / Q000453:epidemiology; D015995:Prevalence; D012307:Risk Factors