Pulmonary Tuberculosis in Pregnancy

Pulmonary tuberculosis in pregnancy is infection of the lungs by Mycobacterium tuberculosis in a pregnant woman. It is common in Kenya, especially with HIV, and untreated disease is more dangerous to mother and baby than the drugs. It causes preterm birth, low birth weight, perinatal death and, rarely, congenital tuberculosis.

• Risk factors: HIV, malnutrition, close contact, diabetes, smoking, previous tuberculosis.
• Standard treatment is compatible with pregnancy and breastfeeding.
• Delay in treatment is the main cause of harm.

Women have cough for 2 weeks or more, fever, night sweats, weight loss and sometimes haemoptysis, with poor weight gain in pregnancy. Examination may be normal or show crackles, wasting and lymph nodes.

• Cough of 2 weeks or more, weight loss and night sweats.
• Chest signs may be minimal.
• Differential diagnosis: pneumonia, HIV related lung disease, pneumocystis pneumonia, lung abscess, sarcoidosis, lung cancer, asthma.
• Complications: respiratory failure, spread to other organs, tuberculous meningitis, preterm birth, low birth weight, congenital and neonatal tuberculosis, maternal death.

The approach is a rapid molecular test with chest imaging.

• Sputum Xpert MTB/RIF (also detects rifampicin resistance), sputum smear for acid fast bacilli and culture.
• Chest X-ray with abdominal shielding.
• HIV test and CD4 count; urine lipoarabinomannan test in advanced HIV; lymph node aspirate for extrapulmonary disease.
• Liver enzymes, creatinine, full blood count at baseline.

The principle is to start full treatment at once, with pyridoxine, and to protect the newborn.

• Supportive: nutritional support; infection control (cover the mouth, ventilate rooms); counsel on adherence and directly observed treatment; breastfeeding with a mask is allowed.
• Pharmacological: intensive phase of 2 months with rifampicin 10 mg/kg (maximum 600 mg), isoniazid 5 mg/kg (maximum 300 mg), pyrazinamide 25 mg/kg and ethambutol 15 mg/kg oral once daily, given as fixed dose tablets by weight (30 to 37 kg 2 tablets, 38 to 54 kg 3 tablets, 55 to 70 kg 4 tablets, above 70 kg 5 tablets); continuation phase of 4 months with rifampicin 10 mg/kg and isoniazid 5 mg/kg oral once daily; pyridoxine 50 mg oral daily throughout; avoid streptomycin and other aminoglycosides.
• Procedures: none.
• Special groups: HIV: start antiretroviral therapy within 2 weeks if CD4 is below 50 and within 2 to 8 weeks otherwise, using tenofovir 300 mg, lamivudine 300 mg and dolutegravir 50 mg oral once daily, with a second dolutegravir 50 mg oral dose 12 hours later during rifampicin treatment and for 2 weeks after, plus co-trimoxazole 960 mg oral daily; the newborn of a smear positive mother receives isoniazid 10 mg/kg oral daily for 6 months (after excluding active disease) with pyridoxine and vitamin K 1 mg IM at birth; rifampicin resistant disease needs referral to a specialist unit.
• Red flags: haemoptysis, jaundice, visual change on ethambutol, severe breathlessness, severe headache or neck stiffness, drug rash.
• Follow-up: monthly review with weight and adherence; sputum smear at 2 and 5 months; liver enzymes if symptoms; infant review at 6 weeks; BCG after completing infant isoniazid.