Antituberculous therapy in pregnancy. Risks to the fetus.

A total of 1,939 reported births to mothers who received isoniazid ethambutol, rifampin and streptomycin alone or in combination, for all or part of their pregnancies, were surveyed to determine teratogenicity of these agents. There was no significant increase in birth defects with isoniazid, ethambutol and rifampin, in contrast to the use of streptomycin which was associated with mild auditory and vestibular defects. Guidelines for the treatment of active tuberculosis in pregnancy are therefore established.