Auditory Brainstem Response Pass Rates Correlate with Newborn Hour of Life and Delivery Mode.

OBJECTIVE

To determine whether hour of life and mode of delivery affect auditory brainstem response (ABR) results in healthy infants with a gestational age of >35 weeks.

STUDY

DESIGN

This retrospective cohort study reviewed 31 984 infants tested during a standard birth hospitalization from 2014 to 2016 at Prentice Women's Hospital of Chicago. Per policy, ABRs were performed after 6 and 12 hours of life for vaginally and cesarean-delivered infants, respectively. Testing was repeated before discharge for infants who were referred once. For those infants who referred again, a third ABR was offered at no cost to families 10-14 days after discharge starting in 2016.

RESULTS

ABR pass rates consistently and significantly increased with advancing hour of life at testing, starting at 10-11 hours of life for vaginally born infants and 30-32 hours for cesarean-born infants. This steady, incremental increase in the pass rate was maintained overall until the vaginal and cesarean groups reached plateaus at 42-44 and 48-52 hours of life, respectively. In 2016 and beyond, a third hearing screen after discharge lowered the referral rate to just 0.77%.

CONCLUSIONS

This study of the results of ABR tests in over 30 000 well newborns demonstrates that delaying hearing screening until 10-11 hours for vaginally born infants and 30-32 hours for cesarean-born infants results in a statistically significant improvement in hearing pass rates.