Hearing impairment in premature newborns-Analysis based on the national hearing screening database in Poland

The incidence of sensorineural hearing loss is between 1 and 3 per 1000 in healthy neonates and 2-4 per 100 in high-risk infants. The national universal neonatal hearing screening carried out in Poland since 2002 enables selection of infants with suspicion and/or risk factors of hearing loss. In this study, we assessed the incidence and risk factors of hearing impairment in infants ≤33 weeks' gestational age (wga).

We analyzed the database of the Polish Universal Newborns Hearing Screening Program from 2010 to 2013. The study group involved 11438 infants born before 33 wga, the control group-1487730 infants. Screening was performed by means of transient evoked otoacoustic emissions. The risk factors of hearing loss were recorded. Infants who failed the screening test and/or had risk factors were referred for further audiological evaluation.

Hearing deficit was diagnosed in 11% of infants ≤25 wga, 5% at 26-27 wga, 3.46% at 28 wga and 2-3% at 29-32 wga. In the control group the incidence of hearing deficit was 0.2% (2.87% with risk factors). The most important risk factors were craniofacial malformations, very low birth weight, low Apgar score and mechanical ventilation. Hearing screening was positive in 22.42% newborns ≤28 wga and 10% at 29-32 wga and in the control group.

Hearing impairment is a severe consequence of prematurity. Its prevalence is inversely related to the maturity of the baby. Premature infants have many concomitant risk factors which influence the occurrence of hearing deficit.