Auditory Brainstem Response in Intrauterine Growth Restriction.

PURPOSE: The purpose of this study was to evaluate the auditory brainstem response (ABR) of infants with asymmetric intrauterine growth restriction (IUGR) in response to different stimuli and to compare the findings with those of term infants.

METHOD: A total of 20 infants with asymmetric IUGR who had no risk factors for hearing loss and 20 term healthy infants as a control group participated. Click, chirp, and 4-kHz tone burst at 90 dB nHL stimuli were used, and Waves I, III, and V absolute latencies; Waves I-III, I-V, and III-V interpeak intervals; and wave amplitudes were evaluated.

RESULTS

The Wave V absolute latency and Waves I-V interpeak interval of both click and chirp stimuli in infants with asymmetric IUGR were significantly shorter in both ears (p < .05). In contrast, only Wave III absolute latency was significantly shorter for both ears (p < .05) with a 4-kHz tone burst.

CONCLUSIONS

ABR test with click, chirp, and 4-kHz tone-burst stimuli revealed that there are functional differences attributed to IUGR. Contrary to popular belief, these findings are evidence of neurosensory changes caused by IUGR, which is not included as a risk factor in newborn hearing screening programs. The type of stimulus used in the assessment was critical.