Teratology of the antituberculosis drugs.

The teratogenic effects of twelve antituberculosis drugs in animal models and man are reviewed. A number of congenital malformations have been associated with the use of these agents; however, for the most part, the birth defect rate is not above that expected for the normal population. Isoniazid and ethambutol are considered the safest for maternal use. Although rifampicin appears to be more problematic, if the disease is severe or extensive, it may be added, preferably after the first trimester. Streptomycin and kanamycin are associated with eighth cranial nerve damage and should be avoided if possible during cyesis. At least five of these compounds have documented evidence of transplacental passage. In consideration of the number of drugs that are available for treatment, routine therapeutic abortions in pregnant females with tuberculosis is not medically indicated.