Patterns of deafness in newborns.

The Crib-o-gram neonatal hearing screening project has detected 42 babies with handicapping degrees of hearing loss, mainly sensorineural. In apparently normal newborns the incidence is 1:1000 births. For graduates of the sick baby (intensive care) nursery, it is 1:52. Intrauterine and neonatal anoxia occurred in 73% of the latter group and was clearly the most common risk factor. Aminoglycosides had no obvious effect. The correlation between specific items in the medical histories and threshold pure tone audiograms was poor and unpredictable for any individual child. In general, anoxia tends to be associated with increased high-frequency hearing loss. Hearing losses were asymmetrical in 43% and probably progressive in 32% (average increase, 33 db). Only one child may have developed the hearing loss after hospital discharge, thus indicating that most, if not all, early childhood deafness is present in the neonatal period.