Teratogenic hearing loss.

Abstract

The total incidence of congenital defects, as reported by various authors, varies considerably with figures ranging from 1 to 3% depending on geographic locality and ethnic origin basis and only in a few percent the cause of the congenital defect can be traced to a known environmental factor. In contrast to other defects, congenital hearing impairment is often attributable to exogenous agents affecting the fetus during pregnancy. Nevertheless, in congenitally deaf children, the unknown etiological group remains the largest and here the most important object for future research is to recognize hitherto unknown exogenous agents, with the ultimate aim of preventing such causes of deafness. A brief survey is given on the present state of knowledge on the harmful effects of drugs and infections on the fetus's hearing organ, supplemented with some personal observations.