What is the appropriate treatment for influenza A in a 32‑week pregnant woman with asthma?

Treatment of Influenza A at 32 Weeks Gestation with Asthma

Start oseltamivir 75 mg orally twice daily immediately, regardless of symptom duration, and continue albuterol as the preferred short-acting bronchodilator for asthma management throughout treatment. 1, 2

Immediate Antiviral Therapy

• Oseltamivir is FDA-approved for treatment of acute, uncomplicated influenza A and B in patients who have been symptomatic for no more than 48 hours, and should be initiated as soon as possible. 1
• Pregnant women with suspected influenza should receive prompt empiric antiviral therapy regardless of rapid influenza diagnostic test results or vaccination status, as rapid tests have poor sensitivity (only 14% positive in one series of PCR-confirmed cases). 3
• Dosing is oseltamivir 75 mg orally twice daily, initiated immediately upon clinical suspicion without waiting for laboratory confirmation. 4
• Early oseltamivir treatment is critical to avoid severe complications, particularly in pregnant women with asthma who face compounded respiratory risks. 4

Concurrent Asthma Management

Bronchodilator Therapy

• Albuterol remains the preferred short-acting β2-agonist during pregnancy, with safety data from over 6,600 pregnant women showing no evidence of fetal harm. 5, 2
• For acute symptoms: 2-4 puffs via metered-dose inhaler every 20 minutes for up to 3 doses, then every 1-4 hours as needed. 2
• For severe exacerbations: combine albuterol 2.5 mg with ipratropium 0.5 mg via nebulizer every 20 minutes for 3 doses, then every 2-4 hours as needed. 2, 5

Systemic Corticosteroids

• Add oral prednisone 40-60 mg daily for 3-10 days if bronchodilators alone do not produce rapid improvement. 6, 2
• For severe exacerbations requiring hospitalization: prednisone 120-180 mg/day divided into 3-4 doses for 48 hours, then 60-80 mg/day until peak expiratory flow reaches ≥70% of predicted or personal best. 2, 6
• Oral corticosteroids are as effective as intravenous when gastrointestinal absorption is intact. 2

Controller Therapy Optimization

• Ensure the patient is on adequate inhaled corticosteroid therapy; budesonide is the preferred agent during pregnancy with safety data from over 2,500 infants showing no increase in congenital malformations (3.6% observed vs 3.5% background rate). 5, 2

Critical Monitoring at 32 Weeks Gestation

Maternal Monitoring

• Maintain maternal arterial oxygen saturation above 95% for fetal well-being. 2
• Monitor maternal heart rate, blood glucose, and potassium levels during β-agonist therapy, as albuterol can cause tachycardia, hyperglycemia, and hypokalemia. 2
• Perform spirometry after the acute episode to objectively confirm treatment response and guide controller therapy adjustments. 2

Fetal Surveillance

• Initiate serial ultrasound examinations immediately at 32 weeks gestation and continue throughout the remainder of pregnancy to monitor fetal growth and detect intrauterine growth restriction. 2, 7
• This surveillance is particularly critical after severe maternal exacerbations or in women with moderate-to-severe or suboptimally controlled asthma. 2, 7
• Instruct the patient to monitor fetal movements closely as an additional safety measure. 2
• Fetal heart rate monitoring should be performed if maternal tachycardia develops from systemic β-agonist administration. 2

High-Risk Context

• Pregnant women with asthma infected with influenza face substantially elevated risks: in one series, 88% required hospitalization, 53% required mechanical ventilation, 29% required emergent cesarean delivery, and 24% died. 3
• Influenza vaccination during pregnancy is recommended but was received by only 14% of critically ill pregnant women in one surveillance series. 3, 7
• Uncontrolled asthma during pregnancy increases risks of perinatal mortality, pre-eclampsia, preterm birth, low birthweight, gestational diabetes, and cesarean section. 7
• The risks of untreated influenza and uncontrolled asthma far exceed any theoretical medication risks; aggressive treatment is mandatory. 2, 3

Common Pitfalls to Avoid

• Do not withhold oseltamivir due to pregnancy concerns—influenza poses greater maternal and fetal risks than antiviral therapy. 3, 4
• Do not wait for laboratory confirmation before starting oseltamivir—rapid tests are unreliable (86% false negative rate in PCR-confirmed cases), and treatment efficacy decreases with delay. 3
• Do not reduce or discontinue asthma medications during pregnancy—uncontrolled asthma poses greater fetal risk than the medications used to treat it. 2, 5
• Do not rely on symptom duration cutoffs—while oseltamivir is FDA-approved for use within 48 hours of symptom onset, pregnant women with asthma warrant treatment even if presenting later due to their high-risk status. 1, 3