Screening to detect permanent childhood hearing impairment in neonates transferred from the newborn nursery.

OBJECTIVES: The focus of this report is hearing screening of newborns transferred from the regular nursery to a specialized area. The purpose of the study undertaken was: (1) to determine whether screening coverage in this population was achieved; (2) to establish whether the linkage between neonatal screening and the diagnostic follow-up was carried out correctly; (3) to better determine the incidence of permanent childhood hearing impairment (PCHI) in this at-risk population.

METHODS: Six population centres averaging 12,000 births annually participated (Bordeaux, Lille, Paris, Marseille, Toulouse and Lyon). Automated auditory brainstem response (AABR) (Natus ALGO 3i) screening was performed in two stages: i.e. infants with initial "positive" results were screened a second time using the same technique. Of the 117,103 babies born during the study period, 4972 neonates were "transferred" and comprised the population for this report (4.2% of the total births).

RESULTS AND DISCUSSION: Screening results for 4972 "transferred" neonates were compared with those of non-transferred neonates (N=112,131). Screening coverage of eligible infants was significantly lower (75.4%) in "transferred" neonates (3750 infants screened) compared to 97.5% coverage of non-transferred neonates (109,349 infants screened). The rate of positive results after the first stage AABR was higher in the "transferred" population (11.1%) than in the non-transferred population (6.5%). Of the 415 "transferred" newborns with initial positive screens, 91.3% were rechecked as stipulated in the project protocol. The second pre-discharge AABR ascertained that in half of the cases auditory function had normalized in the day. Of the 183 "transferred" infants whose result remained suspect at the conclusion of both stages of the neonatal screen (4.9% of the tested population), only 70.5% returned to the audiology centre for diagnostic follow-up. The incidence of bilateral PCHI was markedly higher (4/1000) in "transferred" infants than in the non-transferred population (1.08/1000).

CONCLUSIONS: The difficulty of obtaining universal screening coverage in "transferred" infants was, unfortunately, verified in this prospective, multicentre study. Further, the diversity of our "transferred" population was not much greater than that revealed by careful analysis of published hearing screening studies in neonatal intensive care unit (NICU) infants. The influence of risk factors and their more or less complex combinations is apparent.