Dr Henrica (Irma) Van Straaten1, Karin S. de Graaff-Korf1, Dr Paul Verkerk2, Dr Paula van Dommelen2
1Isala Clinics, Dept of Neonatology, Zwolle, The Netherlands,
2TNO, Department of Child Health, Leiden, The Netherlands
Objective: Is brain development with respect to auditory pathways faster in utero or outside utero?
Study design: From 1998-2016 2-stage AABR hearing screening was performed in immature newborns 25-27 weeks, very preterm newborns 28-30 and newborns with a gestational age (GA) of 31 weeks. Only newborns without hearing loss were included. AABR results were obtained from the nationwide screening program up to 46 weeks postmenstrual age. The assumption was made that once a pass resulted this was also a pass afterwards. Also, we assumed that if the newborn had a refer at a certain postmenstrual age the previous results would have been a refer as well. Multiple imputation was used to predict the missing data (for example with a refer at 35 weeks’ postmenstrual age and a pass at 40 weeks’ postmenstrual age, there is missing data between 36-39 weeks’ postmenstrual age). In total, ten predictions were conducted and afterwards pooled.
Results: In total, 23,964 newborns with 28,754 AABR results were eligible. GA had a significant (p<0.001) and clinically relevant effect on the time of passing the AABR after adjustment for postmenstrual age. Pass rates of approximately 80% could be obtained at 35, 33, 32, and 31 weeks’ postmenstrual age in newborns born at respectively 25, 26-27, 28, and 29-31 weeks GA. Pass rates of approximately 90% could be obtained at 37, 36, 35, 34, 33, and 32 weeks’ postmenstrual age in newborns born at respectively 25, 26, 27, 28, 29, and 30-31 weeks GA.
After adjustment for postmenstrual age in very preterm newborns, lower GA is associated with lower pass rates in AABR hearing screening. This finding suggests that functional auditory development is increasingly delayed with decreasing GA of the newborn.
Dr HLM (Irma) van Straaten is neonatologist. She implemented and guided since1998 for 20 years a nationwide Dutch AABR NICU neonatal hearing screening program as medical coordinator as wel as research items in this field.