Is it reasonable to prescribe a short course of oral prednisolone to a woman in early pregnancy who has had weeks of chronic sinusitis and an acute asthma flare?

Yes, a short course of oral prednisolone is reasonable and indicated in this clinical scenario.

In a pregnant woman with an acute asthma flare, the benefits of systemic corticosteroids substantially outweigh the potential fetal risks, as uncontrolled asthma poses greater danger to both mother and fetus than the medication itself 1, 2.

Clinical Rationale

The 2020 ERS/TSANZ guidelines explicitly state that "the major benefit of systemic corticosteroids in severe asthma exceeds the possible fetal risk" 1. This is critical because:

• Uncontrolled asthma during pregnancy is associated with maternal and/or fetal mortality 2
• Severe asthma exacerbations increase risks of pre-eclampsia, preterm delivery, and low birth weight 1
• Only 10% of maternal prednisolone concentration reaches fetal blood 1

Safety Profile in Early Pregnancy

While there are conflicting data regarding first trimester use:

Reassuring evidence: Multiple studies show no increase in birth defects with prednisolone use 1

Concerning evidence: Some studies suggest a 3-fold increased risk of isolated cleft lip ± cleft palate with first trimester systemic corticosteroid use 1

However, this absolute risk remains small, and the guideline consensus is clear that benefits outweigh risks when treating acute asthma exacerbations.

Dosing Approach

For acute asthma exacerbations in pregnancy 2, 3:

• Use prednisolone 0.5-1 mg/kg/day
• Typical course: 5-10 days
• No need to taper if duration <10-14 days
• Use the lowest effective dose for the shortest duration necessary

Important Caveats

1. Inhaled corticosteroids should be optimized first - Budesonide is the preferred inhaled corticosteroid during pregnancy (TGA Category A) 1, 2

2. For chronic rhinosinusitis alone - Consider intranasal corticosteroids as first-line rather than systemic steroids 4. However, given the concurrent asthma flare, systemic treatment is justified.

3. Monitor for adrenal insufficiency - If high-dose steroids continue until delivery, the newborn should be monitored for adrenal insufficiency 1

4. Document informed consent - Discuss both the small potential risks of medication and the substantial risks of uncontrolled asthma 5

Common Pitfall to Avoid

Research shows that pregnant women are undertreated for asthma exacerbations compared to when they are not pregnant, with delayed and reduced use of systemic corticosteroids 6. This therapeutic hesitation is more harmful than appropriate steroid use. The evidence demonstrates that concerns about fetal safety often lead to inadequate asthma control, which paradoxically increases maternal and fetal risks 7, 8.

The key principle: Maintaining maternal asthma control is the most important factor for optimal pregnancy outcomes, and this sometimes requires systemic corticosteroids 1, 2.