Asthma Medication Safety During Pregnancy and Breastfeeding: What You Need to Know

When you’re pregnant or breastfeeding and have asthma, the last thing you want to do is harm your baby. But the fear of using your inhaler can be stronger than the fear of not breathing. You’re not alone. Around 8% of pregnant women have asthma, and nearly 20-25% of them stop taking their meds because they’re scared. That’s dangerous. Uncontrolled asthma puts both you and your baby at risk for preterm birth, low birth weight, and even preeclampsia. The truth? Most asthma medications are not just safe-they’re necessary.

Why Skipping Your Inhaler Is Riskier Than Using It

Many women think, "If I don’t take anything, my baby won’t be exposed." But here’s the reality: if you can’t breathe, your baby can’t breathe either. Oxygen levels drop during an asthma flare. That’s not hypothetical. Studies show that babies of mothers with poorly controlled asthma are 30-40% more likely to have complications or even die before or right after birth compared to babies of mothers with well-managed asthma.

One National Jewish Health study tracked 327 pregnant women with asthma who stuck to their treatment plans. Over 98.7% of their babies were born at full term with normal birth weights. In the group that skipped or cut back on meds, only 76.4% had healthy outcomes. The difference isn’t small. It’s life-changing.

What Medications Are Safe During Pregnancy?

Not all asthma meds are created equal. The safest options are the ones you breathe in-not swallow.

• Inhaled corticosteroids (ICS) like budesonide (Pulmicort) are the gold standard. Less than 10-30% of the dose even reaches your lungs, and almost none crosses the placenta. Over 10,000 pregnancy outcomes have been tracked-and no increase in birth defects has been found.
• Short-acting beta agonists (SABAs) like albuterol (Ventolin, ProAir) are your rescue inhaler. They work fast, last a few hours, and have been studied for decades. No link to birth defects at standard doses (90-180 mcg per puff).
• Leukotriene modifiers like montelukast (Singulair) are taken as pills. While less studied than inhalers, current data shows no major risks. Milk levels in breastfeeding are far below what’s safe for infants over six months.

Oral steroids like prednisone? They’re okay for short bursts during flare-ups. But long-term use isn’t recommended unless absolutely necessary. Even then, doses under 40mg daily for five days are unlikely to affect your baby.

What About Breastfeeding?

Breastfeeding doesn’t mean you need to stop your meds. In fact, doctors strongly advise continuing them.

The key? Inhalers. When you use an inhaler, the medicine goes straight to your lungs. Very little enters your bloodstream. And even less makes it into your breast milk.

• Albuterol: Less than 0.1% of the dose shows up in breast milk. No effect on babies.
• Prednisolone: Only 5-25% of your blood level transfers to milk. Even at 40mg daily for five days, the amount your baby gets is tiny. If you’re on higher doses long-term, you might pump and dump for a few hours after taking it-but most moms don’t even need to.
• Theophylline: Less than 1% of your dose ends up in milk. It’s safe, but requires blood level monitoring.

The Breastfeeding Network in the UK says it plainly: "Asthma inhalers do not produce levels of drug in the blood system let alone in milk so are safe to use as normal." You don’t need to time your doses around feedings. You don’t need to pump and dump. Just use your inhaler like you always have.

What’s Not Safe-or Not Enough Known?

There’s one big gap: newer medications.

Biologics like omalizumab (Xolair), mepolizumab (Nucala), and dupilumab (Dupixent) are powerful tools for severe asthma. But they’re relatively new. There’s not enough data yet on how they affect developing babies or nursing infants. The FDA lists them as Category B, meaning no harm was seen in animal studies-but human data is limited.

The American Academy of Allergy, Asthma & Immunology (AAAAI) says: "Newer agents have less established safety profiles during breastfeeding." So if you’re on one of these, talk to your doctor before getting pregnant. Don’t stop cold turkey-but don’t assume it’s automatically safe either.

What You Should Do Before and During Pregnancy

Don’t wait until you’re pregnant to figure this out. If you’re planning a pregnancy, schedule a check-up with your asthma specialist and OB-GYN. Together, you can:

1. Create a personalized asthma action plan.
2. Review your current meds and switch to safer options if needed (budesonide is often preferred over other steroids during pregnancy).
3. Learn how to use your inhaler properly-many people use them wrong, which reduces effectiveness.
4. Set up regular check-ups: every 4-6 weeks during pregnancy, not every few months.
5. Get a peak flow meter and track your breathing at home. Your lung capacity drops naturally by 5-10% in late pregnancy. That’s normal. Don’t panic if your numbers dip slightly.

Common Myths and Misconceptions

Myth: "Shortness of breath means my asthma is getting worse." Truth: Almost 70% of pregnant women feel more winded as their belly grows-even if they don’t have asthma. That’s just your body making room for the baby. If you’re wheezing, coughing, or needing your inhaler more than usual, then yes-your asthma might be flaring. But if you’re just breathing harder after climbing stairs? Probably normal.

Myth: "I should stop my meds if I’m breastfeeding." Truth: No. The amount of medicine in breast milk is so tiny it’s practically zero. Your baby gets more medication from your skin cream than from your inhaler.

Myth: "I’ll be fine if I just avoid triggers." Truth: Avoiding triggers helps-but it’s not enough. Asthma is a chronic condition. It needs ongoing treatment. Even if you feel fine, your airways are still inflamed. That inflammation is what puts your baby at risk.

What Happens When Women Stop Their Meds?

The data is clear: stopping asthma meds during pregnancy leads to worse outcomes.

An Asthma and Allergy Foundation of America survey found that 22% of pregnant women reduced or stopped their medications without talking to a doctor. Among those women, 37% ended up in the emergency room. In the group that stayed on their meds? Only 12% had ER visits.

One mother in Melbourne shared her story: She stopped her inhaler in her second trimester because she was scared. Two weeks later, she had a severe attack. Her baby was born two weeks early. She says now: "I thought I was protecting him. I was putting him in danger."

What’s Changing in 2026?

The NIH just launched a $4.7 million registry in 2024 to track 5,000 pregnancies where mothers used asthma medications. Results won’t come until 2027, but this is the biggest step yet toward real, human data.

The American Thoracic Society is also funding studies on how biologics move into breast milk. We’ll know more by 2026. Until then, stick with what’s proven: inhaled steroids and SABAs.

Final Advice: Trust the Science, Not the Fear

Your doctor isn’t trying to push pills on you. They’re trying to keep you alive and your baby healthy. The evidence isn’t just opinion-it’s decades of real-world outcomes.

If you’re pregnant or breastfeeding and have asthma:

• Keep using your inhaler. It’s safer than not using it.
• Don’t switch or stop meds without talking to your care team.
• Use your peak flow meter and track your symptoms.
• Go to every appointment-even if you feel fine.
• Remember: if you can’t breathe, neither can your baby.

You’re not being reckless by taking your medication. You’re being responsible. And your baby will thank you for it.