Risk factors for hearing loss in pre-term newborns: evaluation with auditory evoked potentials

Tonaltlacal A. López-González, Biology and Optometry Section, FES Iztacala, Universidad Nacional Autónoma de México, Mexico City, Mexico
María A. González-Velázquez, Department of Neuroscience, Instituto Nacional de Perinatología Isidro Espinosa de los Reyes, Mexico City, Mexico
Sarahi M. López-Martínez, Department of Neuroscience, Instituto Nacional de Perinatología Isidro Espinosa de los Reyes, Mexico City, Mexico
Efraín Olivas-Peña, Department of Neuroscience, Instituto Nacional de Perinatología Isidro Espinosa de los Reyes, Mexico City, Mexico
Blanca E. Farfán-Labonne, Department of Physiology and Cell Development, Instituto Nacional de Perinatología Isidro Espinosa de los Reyes. Mexico City, Mexico

Background: Pre-term birth is associated with functional immaturity of the central nervous system, increasing vulnerability to hearing loss. Auditory Brainstem Response (ABR) is a method for evaluating auditory integrity in neonates. Evidence regarding associations between specific neonatal morbidities and ABR alterations in pre-term populations remains limited. Objectives: To identify maternal and neonatal risk factors associated with ABR abnormalities in pre-term newborns. Methods: A retrospective observational analytical study was conducted using medical records of newborns who underwent ABR testing between January 2022 and January 2023 at the Instituto Nacional de Perinatología. The sample included 158 newborns (< 38 weeks of gestation) with technically adequate ABR studies. Absolute latencies (waves I, III, V) and interpeak intervals (I–III, III–V, I–V) were analyzed. Newborns were categorized according to the presence or absence of ABR alterations. Associations between neonatal pathologies and ABR abnormalities were evaluated. Results: Mean gestational age was 32.6 ± 4.0 weeks, and mean birth weight was 1,648 ± 790 g. Overall, 34.8% presented ABR alterations. Neonatal sepsis (p = 0.001), bronchopulmonary dysplasia (BPD) (p = 0.002), patent ductus arteriosus (PDA) (p = 0.005), intrauterine growth restriction (p = 0.046), and retinopathy of prematurity (p = 0.017) were significantly associated with hearing loss risk. Significant differences were observed in interpeak intervals I–III (p = 0.028) and I–V (p < 0.001) in the right ear, and I–V (p = 0.043) in the left ear, with bilateral alterations predominating. Conclusions: Neonatal sepsis, BPD, and PDA were significantly associated with ABR alterations in pre-term newborns, supporting strengthened auditory surveillance strategies for early detection and intervention.

Keywords: Hearing loss. Pre-term. Brainstem auditory evoked potentials. Neonatal sepsis. Bronchopulmonary dysplasia.