When you're pregnant or breastfeeding and have asthma, the biggest question isn't just how to manage your symptoms-it's whether your medication is safe for your baby. Many women worry that using their inhaler could harm their unborn child or pass dangerous chemicals through breast milk. But the truth is simpler than the fear suggests: uncontrolled asthma is far more dangerous than most asthma medications. Stopping your treatment because you're scared of side effects puts both you and your baby at greater risk than continuing it.

Why Asthma Control Matters More Than You Think

Asthma affects about 8% of pregnant women. That’s more than 1 in 12. If your asthma isn’t well-managed during pregnancy, you’re at higher risk for serious complications like preeclampsia, preterm labor, low birth weight, and even stillbirth. Studies show that when asthma is poorly controlled, babies are 30-40% more likely to have health problems at birth compared to those whose mothers kept their asthma under control. Oxygen levels matter-when you struggle to breathe, your baby struggles too. Your baby gets all its oxygen from you. If your airways are tight or inflamed, less oxygen reaches the placenta. That’s why doctors say: if you can’t breathe, neither can your baby.

Yet, around 20-25% of pregnant women stop or reduce their asthma medications out of fear. A 2023 survey by the Asthma and Allergy Foundation of America found that 22% of pregnant women with asthma reduced or stopped their meds without talking to a doctor. Those women were nearly three times more likely to end up in the emergency room than those who stayed on their treatment plan.

What Medications Are Safe? The Simple Breakdown

Not all asthma meds are the same. The safest options are the ones you breathe in-not the ones you swallow. Inhaled medications work directly in your lungs, with very little entering your bloodstream. That means almost nothing reaches your baby.

• Inhaled corticosteroids (ICS) like budesonide (Pulmicort) are the gold standard. Over 10,000 pregnancy cases have been studied, and no increased risk of birth defects has been found. Budesonide is often the first choice because it’s been used the longest and has the most data. Other ICS like fluticasone and mometasone are also considered safe.
• Short-acting beta agonists (SABAs) like albuterol (Ventolin, ProAir) are rescue inhalers. They work fast to open your airways. Studies show no increased risk of birth defects at standard doses (90-180 mcg per puff). If you need to use it more than twice a week, your asthma isn’t well-controlled-and you need to adjust your long-term plan.
• Long-acting bronchodilators (LABAs) like formoterol and salmeterol are usually paired with ICS. They’re safe when used together, but should never be used alone. The American Academy of Allergy, Asthma & Immunology says these are appropriate for persistent asthma during pregnancy if needed.
• Leukotriene modifiers like montelukast (Singulair) have limited data but are generally considered acceptable. Studies show the amount that passes into breast milk is far lower than the dose given to infants.

Oral medications? Avoid them unless absolutely necessary. Pills like prednisone or theophylline cross the placenta more easily and carry higher risks. If you need them, your doctor will use the lowest possible dose for the shortest time.

What About Breastfeeding?

Here’s the good news: almost all asthma medications are safe while breastfeeding. The amount that enters your milk is tiny-often less than 1%. For example:

• Albuterol: Less than 0.1% of the dose ends up in breast milk. No effect on the baby.
• Budesonide: Less than 1% transfers into milk. Even at high doses, no side effects reported in nursing infants.
• Prednisolone: Only 5-25% of your blood level shows up in milk. A 40mg daily dose for five days won’t hurt your baby. Higher doses? You might be advised to wait 4 hours after taking it before feeding-but even then, the risk is very low.
• Theophylline: Less than 1% transfers. If you’re on it, monitor your baby for irritability or poor feeding-but most babies show no reaction.

And here’s the key point: you don’t need to time your inhaler around feedings. Unlike some medications, inhaled asthma drugs don’t build up in your blood or milk. You can use them anytime-even right after nursing. Your baby won’t get enough to cause any issue.

What About Newer Medications? Biologics and the Unknown

Drugs like omalizumab (Xolair), mepolizumab (Nucala), or dupilumab (Dupixent) are newer biologics used for severe asthma. They’re not first-line treatments, but if you’re already on one before pregnancy, don’t panic. The FDA lists them as Pregnancy Category B, meaning animal studies show no harm, but human data is still limited. Experts agree that if you’re stable on one of these, continuing through pregnancy is likely safer than stopping and risking a flare-up. For breastfeeding, there’s almost no data. The American Academy of Family Physicians says the transfer into milk is likely minimal, but we don’t have enough studies to say for sure. If you’re considering starting a biologic while pregnant or breastfeeding, talk to your specialist. The risks of uncontrolled asthma still outweigh the unknowns.

What You Should Do: A Clear Action Plan

You don’t need to guess. Here’s what works:

1. Plan ahead. If you’re thinking about getting pregnant, see your asthma doctor and OB-GYN together. Adjust your treatment plan before conception.
2. Keep using your inhaler. Never stop it because you’re scared. Your inhaler is your best tool.
3. Monitor your breathing. Use a peak flow meter at home. Your lung capacity drops a little during pregnancy-this is normal. But if your peak flow drops more than 20% from your baseline, call your doctor.
4. Get checked every 4-6 weeks. Pregnant women with asthma need more frequent visits than non-pregnant patients. Don’t wait for symptoms to get worse.
5. Have an asthma action plan. Know when to increase your inhaler use, when to call your doctor, and when to go to the ER. Keep it handy.
6. Don’t confuse normal pregnancy breathlessness with asthma. Up to 70% of pregnant women feel short of breath in late pregnancy-even without asthma. If your inhaler doesn’t help, or you’re wheezing, coughing, or waking up at night-it’s asthma. If you’re just tired and winded, it’s probably normal.

The Big Misconception: "I’m Pregnant, So I Should Stop Everything"

Many women believe that pregnancy means they should avoid all medications. But that’s not how medicine works. You don’t stop insulin if you’re pregnant and have diabetes. You don’t stop seizure meds if you have epilepsy. Asthma is the same. The medication isn’t the threat-your breathing problems are.

One case study from National Jewish Health followed 327 pregnant women with asthma who stuck to their treatment. Nearly 99% delivered at full term. Their babies’ birth weights were normal. Compare that to the group who stopped or reduced meds: only 76% had normal birth weights, and preterm birth rates jumped.

Doctors don’t recommend these medications because they’re perfect. They recommend them because they’re the safest option available-and stopping them is riskier.

What’s Being Done to Improve This?

Research is moving fast. In 2024, the NIH launched a $4.7 million registry to track 5,000 pregnancies where mothers used asthma medications. The goal? To build the strongest safety data ever on this topic. The American Thoracic Society is also prioritizing studies on how biologics behave in breast milk. By 2026, we’ll have clearer answers.

Hospitals like Kaiser Permanente have already cut preterm births in asthmatic pregnancies by 28% by creating coordinated care pathways between OB-GYNs and pulmonologists. More clinics are adopting this model.

But until the data is fully in, the message stays the same: use your medication. Stay in control. Your baby needs you to breathe.