The effectiveness of the oral contraceptives is reduced when taking rifampicin. Contraceptive advice should be given to all women starting therapy. Rifampicin is not an indication for termination. Pregnant women should receive standard treatment (none of the first line drugs have been shown to be teratogenic in humans). However ethionamide and prothionamide may be teratogenic and should be avoided. Due to a risk of fetal ototoxicity streptomycin and other aminoglycosides should be avoided in pregnancy. Patients can breast feed normally while taking antituberculosis drugs.

Reference

Joint Tuberculosis Committee of the British Thoracic Society. Thorax 1998;53:536-548