19-27: Tuberculosis in Pregnancy

The diagnosis of tuberculosis in pregnancy is made by history taking, physical examination, and testing, with special attention to women in high-risk groups. Women at high risk include those from endemic areas, those infected with HIV, drug users, health care workers, and close contacts of people with tuberculosis. Screening chest radiographs should only be obtained in pregnant patients who have a positive test or with suggestive findings in the history and physical examination. Abdominal shielding must be used if a chest radiograph is obtained. Both tuberculin skin testing and interferon gamma release assays are acceptable tests in pregnancy.

Decisions on treatment depend on whether the patient has active disease or is at high risk for progression to active disease. Pregnant women with active disease or who are high risk for progression should be treated during pregnancy as the risks of complications from tuberculosis outweigh the risks of treatment. Pregnant women with latent disease not at high risk for disease progression can receive treatment postpartum, which does not preclude breastfeeding. The concentration of medication in breast milk is neither toxic nor adequate for treatment of the newborn. Isoniazid, ethambutol, and rifampin are used to treat tuberculosis (see Chapters 9 and 33). Because isoniazid therapy may cause vitamin B₆ deficiency, a supplement of 50 mg/day of vitamin B₆ should be given simultaneously. There is concern that isoniazid, particularly in pregnant women, can cause hepatitis. Liver biochemical tests should be performed monthly in pregnant women who receive treatment. Streptomycin, ethionamide, and most other antituberculous drugs should be avoided in pregnancy. If adequately treated, tuberculosis in pregnancy has an excellent prognosis.