Prevalence of hearing loss in very low birth weight neonates

Objective: To evaluate the prevalence of hearing alterations in very low birth weight patients in the Neonatal Intensive Care Unit of the Hospital de Clinicas de Porto Alegre and to study the variables that can be related to alterations of the hearing acuity. Methods: A transversal study was carried out. The study included all very low birth weight neonates admitted to the Neonatal Intensive Care Unit of the Hospital de Clinicas de Porto Alegre from September 1, 2000 to January 31, 2002. All patients were submitted to distortion product otoacoustic emission tests at hospital discharge. When the test showed alterations, it was repeated 30 days later. However, when the same patient presented otoacoustic emission alterations in both tests, he/she was submitted to the auditory brain response testing. The result of this test was considered abnormal from 35 dB NA. Results: We studied 96 neonates. Six children presented alteration in the distortion product otoacoustic emission test as well as in the auditory brain response test. Children’s mean age was 31.5 ± 2.6 weeks, their birthweight was between 640 g and 1,500 g, and 57.3% of the patients were female. The gestational age and the Apgar score of 5 minutes were inferior in the group presenting abnormal results of otoacoustic emission and auditory brain response tests compared to the other groups, reaching bordering significance. All the remaining aspects investigated did not present any statistically significant difference. Conclusions: The prevalence of hearing loss in the very low birth weight neonates cared for at the Neonatal Intensive Care Unit of the HCPA was 6.3%, and bordering significance associations related to gestational age and 5 minutes Apgar score were observed.