Pregnancy does not mean that patients with tuberculosis must stop treatmentBMJ 1999; 318 doi: https://doi.org/10.1136/bmj.318.7193.1286a (Published 08 May 1999) Cite this as: BMJ 1999;318:1286
- Graham Bothamley, Consultant respiratory physician,
- Will Elston, Specialist registrar
EDITOR—We were disappointed that Rubin's review of drugs that could safely be taken in pregnancy did not mention drugs for tuberculosis.1 Adherence to successful treatment of tuberculosis is essential. In 1998 three patients with tuberculosis (of 114 such patients treated at Homerton Hospital) became pregnant; all three were advised by their general practitioner or midwife to stop their treatment, and two accepted a termination. In addition, two of 71 female patients receiving preventive treatment with isoniazid were advised to stop treatment after a pregnancy test gave a positive result.
The British Thoracic Society's guidelines state: “None of the first line drugs has been shown to be teratogenic…. Streptomycin should be avoided as [it] may be ototoxic.”2 In the United States caution is expressed regarding the use of pyrazinamide, but data do not indicate any adverse effects. 3 4 Hamedeh and Glassroth reviewed the literature concerning over 2000 pregnancies in mothers with tuberculosis and found no significant difference in side effects in these women compared with non-pregnant subjects and no higher incidence of fetal abnormalities; they commented that “there is no indication for the interruption of pregnancy” for those with tuberculosis and that “untreated tuberculosis represents a far greater hazard to a pregnant woman and her fetus than does treatment of the disease.”4
Theoretical considerations suggest that the immune response in pregnancy, which shifts T cell responses away from cell mediated immunity (Th1) and towards antibody help (Th2), could allow tuberculosis to develop in those who have been infected with the tubercle bacillus. The greater proportion of pregnant patients with smear positive pulmonary tuberculosis is in keeping with this hypothesis (usually this form of the disease is more common in men)4; active disease should arise in infected pregnant women more commonly than in others with a positive tuberculin response. Concerns have been raised about the incidence of hepatitis induced by isoniazid during pregnancy,5 although the women may have had concurrent viral hepatitis and differences have not been significant.4
The incidence of hepatitis due to isoniazid increases with age over 35. On these grounds it seems reasonable to complete preventive treatment that has been started but to delay treatment with isoniazid until after delivery in those in whom a tuberculin skin test gives a positive result. Treatment should not, however, be withheld from patients with active disease, nor termination advised.