Hearing screening in a neonatal intensive care unit

Abstract

Objective: Investigate the prevalence of hearing impairment in newborns hospitalized at the Intensive and Intermediate Care Unit at the Women's Comprehensive Health Center Neonatology Service (UNICAMP) and associated risk factors.

Methods: 979 newborn babies were assessed between January 2000 and January 2003, through automated auditory brainstem response (AABR) (ALGO 2e color screener). The result was considered normal when the newborn showed response to a 35dBNA signal bilaterally. The prevalence of AABR impairment and the odds ratio were analyzed with a 95% confidence interval using bivariate analysis. To identify the independent risk factors for hearing alterations, multivariate analyses were used with logistic regression.

Results: The prevalence of AABR impairment was 10.2%, of which 5.3% was unilateral and 4.9% bilateral. From the multivariate analyses, the following observations were made: family history of congenital hearing loss (OR = 5.192; p = 0.016), craniofacial deformity (OR = 5.530; p < 0.001), genetic syndromes associated with hearing loss (OR = 4.212; p < 0.001), weight below 1,000 g (OR = 3.230; p < 0.001), asphyxia (OR = 3.532; p < 0.001), hyperbilirubinemia (OR = 4.099; p = 0.002) and use of mechanical ventilation (OR = 1.826; p < 0.031) were the indicators that best characterized the group at risk for hearing impairment.

Conclusions: The prevalence of hearing impairment using AABR is high. Therefore, it is essential for all newborns who present isolated or associated risk factors to undergo hearing screening in situations in which it is not possible to have universal hearing screening.