Investigação da via auditiva em crianças nascidas a termo pequenas para a idade gestacional: análise comparativa

Abstract

Introduction: Investigations of the auditory system in small for gestational age, born at term newborns have shown that growth restrictions cause alterations and delays in the maturation process of the auditory pathway. In this scenario, the study of the auditory pathway in older children would help to understand the functional development of the auditory systems in this population as they grow. Objective: To investigate the maturation process of the auditory pathway in newborns and in children of between 5 and 9 years of age, small for gestational age. Methods: To respond to the first objective, a systematic review or meta-analysis (article 1) was carried out, researching articles in the main electronic databases that reported assessments of the auditory pathway in small for gestation age full-term newborns, compared with an adequate control appropriate for gestational age, considering articles available in full, without limitation of year of publication. In a second state, an original cross-sectional and analytical study was performed, which included 36 participants, born at full-term, of both genders, and ages between 5 and 9 years, divided into study groups - small for gestational age at full-term (n=24) and a control group, children appropriate for gestational age (n=12). The study analyzed clinical aspects, tonal auditory thresholds, contralateral acoustic reflexes and Brainstem auditory evoked potential. Results: For article 1, 10 studies were included in the systematic review, of which 5 were eligible for meta-analysis, involving a total of 473 participants, with 193 belonging to the group small for gestational and 280 belonging to the control group. Differences were observed in the absolute latency of wave V, CI 95% (0.02- 0.15) p<0.01 (article 1). In the original study (article 2), the hearing thresholds in both groups were within normal range. Statistical differences were observed among the groups in relation to the body weight at birth (p=0.001), acoustic reflexes at the frequency of 2 kHz in the left ear (p=0.032), wave III in the right (p=0.033) and left ear (p=0.021) and in the interpeak interval I-III (p=0.005) in the right ear. Conclusion: In small for gestational age full- term newborns, dysfunctions in sound conduction are observed at the brainstem level, probably due to the delay in the maturation process of the auditory pathway. And, even with preserved auditory sensitivity, older children may present retrocochlear dysfunctions, which could have subtle negative repercussions on the processing of auditory information, with impairment to the development of communicative and cognitive skills.