Epidemiological Study on the Incidence of Hearing Impairment in Children Up to 3 Years of Age and Associated Risk Factors

Early diagnosis of congenital hearing impairment is of great importance to later development and social life of the affected newborns. Otoacoustic emission screening test (OAEs) is a useful tool for early evaluation of hearing in neonates and infants. Some specific risk factors (RFs) associated with prenatal, birth and early postnatal periods may influence the first screening results and further diagnostic findings. Results from OAEs in newborns in University Hospital in Pleven between 2013-2015 years are analyzed. In low birth weight children (under 2500 grams or g), and those born before the 36^th gestation week (GW), we found deviations in the OAEs. A negative test result proved higher in newborns subjected to oxygen therapy during the first hours after birth (15.5%), as well as in newborns with higher leucocytes count (11.0%) or higher serum bilirubin value immediately after birth. The average birth weight of the newborns was lower in the cases with negative test results (2848.7±506.5 g) and unilateral negative test results (2823.3±535.2 g), as compared with the group with positive test results (3191.9±387.9 g). Elevated bilirubin levels were more frequently established and can be expected with higher probability in low birth weight children. They shall be subject to a follow-up in time, and newborns with initial negative test result shall undergo a second test 2 months after birth. Long term monitoring is recommended for newborns with these risk factors.