Pneumonia in Pregnancy

Pneumonia in pregnancy is infection of the lung tissue in a pregnant woman, most often by Streptococcus pneumoniae, Haemophilus influenzae, atypical organisms and viruses including influenza and SARS-CoV-2. Pregnancy lowers lung volume and immunity, so illness is more severe. It matters because it is an important non obstetric cause of maternal death and causes preterm labour.

• Risk factors: HIV, asthma, anaemia, smoking, malnutrition, sickle cell disease, influenza.
• In HIV with low CD4, tuberculosis and Pneumocystis pneumonia must be excluded.
• Early antibiotics lower maternal and fetal risk.

Women have fever, cough with sputum, pleuritic chest pain, breathlessness and tachypnoea, and examination shows crackles or bronchial breathing. Assess respiratory rate, oxygen saturation and blood pressure.

• Respiratory rate above 24 per minute is significant.
• Abdominal pain can occur with lower lobe disease.
• Differential diagnosis: pulmonary tuberculosis, influenza, COVID-19, pulmonary embolism, heart failure, asthma, malaria, pneumocystis pneumonia, aspiration.
• Complications: respiratory failure, sepsis, empyema, preterm labour, fetal distress, low birth weight, maternal death.

The approach is clinical with chest imaging and severity scoring.

• Chest X-ray with shielding; full blood count, urea, creatinine, blood culture, sputum for Gram stain, culture and Xpert MTB/RIF.
• Oxygen saturation; severe if saturation is below 94 percent, respiratory rate is 30 per minute or above, systolic pressure is below 90 mmHg or there is confusion.
• Influenza and COVID-19 tests in season; HIV test; malaria test.
• Cardiotocography after stabilisation.

The principle is early antibiotics, oxygen and monitoring of the fetus, avoiding drugs that harm the fetus.

• Supportive: oxygen to keep saturation at 95 percent or above; oral or IV fluids; left lateral position; paracetamol 1 g oral 6-hourly (maximum 4 g in 24 hours); chest physiotherapy; admit if the respiratory rate is 24 per minute or above or saturation is below 94 percent.
• Pharmacological: mild disease: amoxicillin 1 g oral 8-hourly for 5 days plus azithromycin 500 mg oral daily for 3 days; severe disease: ceftriaxone 2 g IV daily plus azithromycin 500 mg IV or oral daily for 7 days; add metronidazole 500 mg IV 8-hourly for aspiration; add oseltamivir 75 mg oral 12-hourly for 5 days if influenza is likely; avoid doxycycline, tetracycline and fluoroquinolones; enoxaparin 40 mg subcutaneous daily during admission; betamethasone 12 mg IM twice, 24 hours apart, if delivery before 34 weeks is likely.
• Procedures: pleural drainage for empyema; intubation for respiratory failure.
• Special groups: HIV with CD4 below 200 or suspected Pneumocystis pneumonia: co-trimoxazole 15 to 20 mg/kg per day of the trimethoprim component, oral or IV in 3 to 4 divided doses for 21 days, plus prednisolone 40 mg oral 12-hourly for 5 days, then 40 mg daily for 5 days, then 20 mg daily for 11 days, with folic acid 5 mg oral daily; start antiretroviral therapy within 2 weeks.
• Red flags: respiratory rate above 30 per minute, saturation below 92 percent, systolic pressure below 90 mmHg, confusion, haemoptysis, reduced fetal movements.
• Follow-up: review at 48 to 72 hours; repeat chest X-ray at 6 weeks if smoker or age above 50 years or if symptoms persist; growth scan at 2 to 4 weeks; vaccinate against influenza and pneumococcus after recovery.