Tuberculosis is not uncommon during the childbearing period. While genital tuberculosis often results in sterility, extragenital lesions do not prevent conception. Tuberculosis is one of the common infections prevalent in India and may be encountered in 1-2% of pregnant women. In the present scenario, pregnant women who are HIV. positive are at greater risk of having this complication and hence this incidence may increase. All women with suggestive symptoms and history of exposure should be screened for tuberculosis.
INFLUENCE OF PREGNANCY ON PULMONARY TUBERCULOSIS
Though initially it was thought that pregnancy aggravated pulmonary tuberculosis, there is enough evidence now to prove that the course of pulmonary tuberculosis is unmodified during pregnancy. The lesions remaining the same, there is no difference in mortality between pregnant and non-pregnant women.
• Pulmonary tuberculosis does not affect fertility unless there is associated genital tuberculosis.
• Usually there is no effect on the course of pregnancy except for a slight increase in the incidence of abortion and premature labour.
• Tuberculosis only rarely affects the fetus by transplacental passage. The greater danger is the possibility of infection of the newborn by close contact when the mother has open tuberculosis.
DIAGNOSIS
In pregnancy, pulmonary tuberculosis may present with symptoms like cough, sputum, hemoptysis, fever or weight loss. There should be a high index of suspicion for tuberculosis in pregnant or puerperal women with unexplained cough and sputum. Active tuberculosis may even be asymptomatic at times. If there is any clinical indication; chest radiographs must be taken.
MANAGEMENT
The problem in managing a pregnant Patient with tuberculosis is the possible effects on the fetus of the chemotherapeutic drugs used. In patients with active tuberculosis, immediate institution of treatment is of period of gestation. drugs considered safe in recommended irrespective of periods of gestation .Anti-tubercular drugs considered safe in pregnancy are ethambutol,isoniazid and rifampicin.
Recommended regimen in pregnancy:
Isoniazid 5 mg/kg, not to exceed 300 mg daily,
Pyridoxine 50 mg daily is given to reduce the risk of isoniazid induced neuropathy
Rifampicin 10 mg/kg daily, not to exceed 600 mg daily
Ethambutol 5-25 mg/kg daily, not to exceed 2.5 mg daily.
This therapy is given for a period of 9 months. Routine antenatal care should be continued. Fetal monitoring should be done to diagnose intrauterine growth retardation since this has been reported to be slightly higher in pregnancies with tuberculosis.
TOXICITY OF ANTI-TUBERCULAR DRUGS
Isoniazid toxicity includes hepatitis which is more common in younger patients. Monitoring of liver enzymes indicates that 10 to 20 per cent of patients have transient elevation. Therapy needs to be discontinued if their elevation is five times the normal level.
ANTI-TUBERCULAR DRUGS AND TERATOGENICITY
Streptomycin has been proved to be potentially teratogenic and is contraindicated in pregnancy.
Pyrazinamide is bactericidal drug used as first- line treatment in the non-pregnant state but there is inadequate data regarding its teratogenicity. Hence this drug is avoided in pregnancy.
CONGENITAL TUBERCULOSIS This is rare. Tubercule bacillemia may infect the placenta. The fetus may be affected either hematogenously or through the umbilical vein. Alternatively, the fetus may be infected by aspiration of infected contents at delivery.
BREASTFEEDING There is consensus that breast-feeding should not be discouraged. Drug concentration in breast milk is low and has no therapeutic value.
NEONATAL RISKS AND MANAGEMENT
Tuberculin positive mother without active tuberculosis does not pose any risk.
• If a pregnant woman with active tuberculosis is sputum negative in the last 3 months of gestation, the risk to infant is negligible.
• If the mother is sputum positive, then the neonate needs to be evaluated for active tuberculosis. If there is no active tuberculosis in the neonate, it should receive INH prophylaxis for 3 months until the mother's sputum becomes negative.
It is important to make an early diagnosis of tuberculosis and treat it to decrease the maternal morbidity and neonatal morbidity. High-risk groups for tuberculosis should be screened during pregnancy.
These include women with HIV infection and those in close contact with persons having active tuberculosis (especially seen in the lower socioeconomic groups). The poorest results have been shown to occur in patients diagnosed for the first time in puerperium since the disease is usually advanced.