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

When you’re pregnant or breastfeeding and have asthma, the biggest question isn’t just how to control your symptoms-it’s whether your meds could hurt your baby. Many women stop using their inhalers because they’re scared. But here’s the truth: asthma medication safety during pregnancy and breastfeeding is one of the most well-studied areas in maternal health-and the evidence is clear. Not taking your asthma medicine is far riskier than taking it.

Why Uncontrolled Asthma Is More Dangerous Than Medication

It’s easy to assume that avoiding all drugs during pregnancy is the safest choice. But asthma isn’t just a cough or wheeze. When your airways tighten, your body doesn’t get enough oxygen. And if you’re not getting enough oxygen, neither is your baby.

Studies show that women with uncontrolled asthma during pregnancy are 2 to 3 times more likely to have preterm babies, babies with low birth weight, or complications like preeclampsia. In fact, research from the American College of Obstetricians and Gynecologists found that keeping asthma under control can reduce newborn mortality by 30-40%. That’s not a small number. That’s life-saving.

And here’s the kicker: nearly 20-25% of pregnant women with asthma stop their medications because they’re afraid. That’s not bravery-it’s a dangerous myth. The biggest threat isn’t the inhaler. It’s the breath you can’t take.

Which Asthma Medications Are Safe During Pregnancy?

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

Inhaled corticosteroids (ICS) like budesonide (Pulmicort) are the gold standard. They work right where you need them-in your lungs. Only 10-30% of the dose even gets into your bloodstream. The rest is exhaled. That means almost nothing reaches your baby. Over 10,000 pregnancy outcomes have been tracked, and budesonide shows no increase in birth defects. It’s the most studied asthma medicine in pregnancy-and it’s still the first choice.

Short-acting beta agonists (SABAs), like albuterol (Ventolin), are your rescue inhaler. These are safe too. They work fast, last a few hours, and don’t cross the placenta in harmful amounts. National Jewish Health reviewed data from thousands of pregnant women and found no link between standard albuterol use and congenital problems.

Even long-acting bronchodilators like salmeterol (Serevent), when used with an inhaled steroid, are considered safe. They’re not first-line for pregnancy, but if your asthma is moderate to severe and you’re already on them, stopping suddenly is riskier than staying on them.

The bottom line? Inhaled medications are designed to stay local. That’s why doctors recommend them as the first step-not pills.

What About Oral Medications and Systemic Steroids?

Oral steroids like prednisone or prednisolone are a different story. They’re stronger. They go into your blood. But they’re still used when needed.

If you have a bad flare-up, your doctor might prescribe a short course of oral steroids. Five days at 40 mg daily? That’s fine for breastfeeding. Higher doses? You might need to wait a few hours after taking it before nursing, or pump and discard once. But even then, the amount in breast milk is less than 0.1% of your dose.

And here’s something most people don’t know: if you need oral steroids during pregnancy, it’s because your asthma is out of control. That’s the real problem-not the medicine. The goal is to use the lowest dose for the shortest time. But don’t avoid them out of fear. A severe asthma attack is far more dangerous than a short steroid course.

As for theophylline? It’s older, requires blood tests to monitor levels, and isn’t used as often anymore. But if you’ve been on it for years and it’s working, your doctor will likely keep you on it-with close monitoring.

Is It Safe to Breastfeed While Taking Asthma Medication?

Yes. Absolutely.

Here’s the reality: asthma inhalers don’t build up in your blood. That means they don’t show up in breast milk in any meaningful amount. 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.”

Even if a tiny bit gets into your milk, it’s less than what your baby would get from a prescribed infant dose. For example, the amount of prednisolone in breast milk is 5-25% of your blood level-and that’s still far below what’s given to newborns for medical reasons.

Montelukast (Singulair)? The levels in breast milk are so low they’re lower than the dose approved for a 6-month-old baby. No need to time feeds. No need to pump and dump. Just use your inhaler like normal.

And if you’re on a biologic like omalizumab (Xolair)? There’s less data, yes. But no red flags so far. If your asthma is severe and you’re on it before pregnancy, most experts say keep going. Stopping could trigger a life-threatening attack.

What About Newer Asthma Drugs?

Biologics like mepolizumab, dupilumab, or benralizumab are amazing for severe asthma. But they’re newer. And yes, there’s less pregnancy data.

That doesn’t mean they’re unsafe. It just means we don’t have 10,000 cases yet. The FDA still lists them as Pregnancy Category B, meaning animal studies show no harm, and human data is limited but not alarming.

Doctors will usually only recommend them if you’re already on them before pregnancy and doing well. If you’re trying to conceive and haven’t started one yet, your doctor might delay starting until after delivery-unless your asthma is so bad you can’t function.

Bottom line: Don’t let the lack of long-term data scare you into stopping. The risk of uncontrolled asthma still outweighs the unknowns.

What You Should Do Before and During Pregnancy

Don’t wait until you’re pregnant to figure this out.

• See your doctor before conception. Get your asthma under control before you get pregnant. That’s the best gift you can give your future baby.
• Make a written asthma action plan. Include your peak flow targets, when to use your rescue inhaler, and when to call your doctor. Adjust your targets as your pregnancy progresses-your lung capacity drops 5-10% in the third trimester, but that’s normal. Don’t mistake it for worsening asthma.
• Check in every 4-6 weeks. Pregnant women with asthma need more frequent visits than the average patient. Your doctor needs to adjust your plan as your body changes.
• Don’t stop or cut back without talking to your doctor. One survey found 22% of pregnant women reduced or stopped their meds on their own. Those women had a 37% chance of ending up in the ER. Adherent women? Only 12%.

Common Myths Debunked

Let’s clear up some noise.

• Myth: “I can’t use my inhaler because it’s a steroid.” Truth: Inhaled steroids are not the same as the ones bodybuilders use. They’re local, low-dose, and safe.
• Myth: “Shortness of breath in late pregnancy means my asthma is getting worse.” Truth: Up to 70% of all pregnant women feel more winded in the third trimester-even those with no asthma. That’s your growing baby pressing on your diaphragm. If you’re wheezing, coughing, or using your rescue inhaler more than twice a week, then yes-your asthma may be flaring.
• Myth: “If I take medicine, my baby will be addicted.” Truth: Asthma medications don’t cause addiction. They don’t cross the placenta in amounts that affect the baby’s brain or nervous system.

Real Stories, Real Results

One study followed 327 pregnant women with asthma who stuck to their treatment plan. Their babies? 98.7% were born at full term with normal weight. The group that stopped or skipped meds? Only 76.4% had normal birth weights.

Another woman in Durban, South Africa, told her OB she was scared to use her inhaler. She stopped for two weeks. She ended up in the ER with a severe attack. Her baby was born two weeks early. She now says: “I thought I was protecting him. I was hurting him.”

There’s no shame in needing help. There’s only danger in silence.

What’s Changing in 2025?

The NIH just launched a $4.7 million registry to track 5,000 pregnancies where mothers used asthma meds. Results will be out by 2027-and they’ll give us even clearer answers.

Meanwhile, the American Thoracic Society is studying how biologics move into breast milk. We’ll know more by 2026.

Right now, 85% of OB-GYNs follow guidelines to keep asthma meds going during pregnancy. But only 62% of family doctors do the same for breastfeeding. That gap needs closing. You deserve consistent, clear advice.

Final Takeaway: Your Breath Matters

You’re not just taking medicine for yourself. You’re taking it for your baby too. Every breath you take, your baby takes with you. If your asthma isn’t controlled, your baby is holding their breath too.

There’s no perfect drug. But there is a safest choice: the one that keeps you breathing. And that’s almost always the one your doctor prescribed.

Don’t let fear silence your inhaler. Talk to your doctor. Make a plan. Stick to it. Your baby is counting on you to breathe.