Brain maturity in regard to the auditory brainstem response in small-for-date neonates

The auditory brainstem response has been used in neonates at risk of hearing impairment or as a functional measurement of brain maturity. The goal of the present study was to evaluate the auditory brainstem response in small-for-date newborns, in relation to changes observed with fetal maturity in a control group. Compared to controls with similar maturity, a significant delay for the appearance of waves III and V, and between waves I-V was observed in the small-for-date newborns, suggesting an alteration of the auditory pathway within the brainstem rather than an impairment of the peripheral auditive apparatus. Indeed, small-for-date newborns reacted to the test in a similar manner as premature babies in whom such a delay was also observed. Our data would suggest a functional brain immaturity in small-for-date newborns, during the first days of life, in regard to the auditive evoked potential, which may be related to some alterations in brain development reported with fetal malnutrition.