Hearing loss

Biology

Auditory brainstem response

Genetics

Pediatrics

Retrospective cohort study

Absolute threshold of hearing

Gestational age

Sensorineural hearing loss

Internal medicine

Breastfeeding

Medicine

Audiology

Pregnancy

International Journal of Pediatric Otorhinolaryngology

Premature infants are at high risk for hearing loss (HL). The aim of the present study is to assess the frequency of preterm infants affected by HL who experience hearing improvement over months and evaluate possible factors associated with hearing changes.This retrospective study was conducted in a third-level referral audiologic center. Preterm infants with a confirmed diagnosis of sensorineural HL within the first 3 months of life were reassessed at 18 months corrected age using the click-evoked auditory brainstem response between January 1, 2012, and June 30, 2020. The frequency of hearing improvement and associations between possible risk factors and hearing changes were evaluated.A total of 138 preterm infants (71 male and 67 female; mean gestational age: 30+2 weeks) were assessed. The percentages of hearing improvement and hearing threshold normalization were 58.7% (81/138) and 35.5% (49/138), respectively. We observed a higher frequency of hearing improvement among preterm infants who had received exclusive breastfeeding or mixed feeding compared with those who had received exclusive infant formula (80% versus 29.3%, P < 0.001).This study confirms the importance of performing a long audiological follow-up and postponing the indication for cochlear implantation in children with a history of preterm birth. Because of the expression of mesenchymal stem cells and high total antioxidant capacity, breast milk might play a protective role in the auditory system of preterm infants. These findings could have important implications for clinical practice, positively impacting the long-term hearing outcomes of preterm infants.

Hearing outcomes in preterm infants with confirmed hearing loss