Maturation of the auditory system in normal-hearing newborns with a very or extremely premature birth

Literature shows that lower gestational age leads to greater delays in the auditory conduction, which suggests atypical maturation of the brainstem in normal-hearing premature newborns. Our aim is to investigate if there is a difference between the extrauterine and intrauterine maturation of the auditory system in normal-hearing newborns with a very premature (28-31 weeks) or extremely premature (<28 weeks) birth.

Results of the Automated Auditory Brainstem Response Newborn Hearing Screening Program in Dutch Neonatal Intensive Care Units and diagnostic examinations were centrally registered from 1998 to 2016. Normal-hearing newborns with a gestational age of 25-31 weeks were included. Screening results at 32-45 weeks of postmenstrual age were compared between newborns born with different gestational ages. Multiple imputation was used to predict missing screening results. Small for gestational age was defined as birth weight corrected for gestational age < -1.6 standard deviation. Descriptive and (pooled) logistic regression analyses were performed.

23,964 newborns with 28,754 screening results were eligible. At the same postmenstrual age, pass rates were lower when gestational age was lower in normal-hearing newborns with a very and extremely preterm birth. Pass rates of 80% could be obtained at 34-35, 32-33, and 30-32 weeks' postmenstrual age in newborns with 25, 26-27, 28-31 weeks gestational age, respectively. Small for gestational age had an additional negative effect on pass rates.

Analysis of hearing screening data suggests that extrauterine maturation of the auditory system is delayed in normal-hearing newborns with a very or extremely premature birth.