Asthma is the most common lung condition in pregnancy, and the main risk comes from poorly controlled asthma, not from the usual asthma medicines. Global asthma guidance (GINA) advises continuing asthma treatment through pregnancy. One large study even found that people relying only on rescue inhalers took longer to conceive than those using preventer inhalers. The best preconception step: get asthma well controlled now, with a review of your inhaler plan.
Controlled asthma is the goal at every stage
Asthma and getting pregnant
Most people with asthma conceive without any trouble. But one study suggests asthma control may play a role in how quickly. Researchers at the University of Adelaide, publishing in the European Respiratory Journal, analyzed data from the international SCOPE study of more than 5,600 first-time pregnancies; about 10% of participants reported asthma.
- People who used only short-acting reliever inhalers (like albuterol) took about 20% longer on average to conceive, and were about 30% more likely to take more than a year.
- People who used long-acting preventer inhalers conceived as quickly as people without asthma.
This was an observational study, so it cannot prove the inhalers themselves made the difference. One explanation the researchers offered is that relying on rescue inhalers alone may leave underlying inflammation untreated. Their practical conclusion matches what asthma guidelines already say: aim for good control before trying to conceive.
Why control matters in pregnancy
A review in CHEST Physician summarizes what is known: asthma affects an estimated 3.7% to 8.4% of pregnant people in U.S. surveys, and pregnancy changes it unpredictably — roughly a third get worse, a third stay the same, and a third improve. Worsening tends to peak around the sixth month, and the course often mirrors a previous pregnancy.
The same review cites a meta-analysis of more than 1.6 million women linking maternal asthma to higher risks of low birth weight, preterm birth, preeclampsia, and small-for-gestational-age babies, and notes that asthma flares during pregnancy are associated with about twice the risk of low birth weight. A 2024 review in Medicines describes the same pattern and states that poor control and flares, rather than treatment, drive these risks.
That can sound alarming, but it points to something you can act on. Most of the added risk is tied to asthma that is not well controlled — exactly what preconception planning targets.
Please do not stop your controller inhaler
The 2024 Medicines review notes that GINA advises pregnant people with asthma to continue their asthma medications throughout pregnancy and does not recommend reducing asthma therapy until after pregnancy. It also notes that up to a quarter of pregnant people with asthma stop their medication because of worries about the baby — which raises the very risks they are trying to avoid.
What the evidence shows about common asthma medicines, as summarized in the CHEST Physician review:
| Medicine type | What the review reports |
|---|---|
| Inhaled corticosteroids (preventers) | A 16-study meta-analysis found no increased risk of congenital malformations. Budesonide has the most pregnancy data, but someone well controlled on another inhaled steroid may continue it. |
| Short-acting relievers (albuterol) | Albuterol is the preferred rescue inhaler; meta-analysis found no increased malformation risk. |
| Long-acting bronchodilators (LABA) | Used only together with an inhaled steroid. Pregnancy data are more limited; one study found no difference in malformation rates with LABA/inhaled-steroid combinations. |
| Leukotriene modifiers | Montelukast and zafirlukast were formerly placed in the FDA’s lower-risk pregnancy category; zileuton is avoided based on animal data. |
| Oral steroids for flares | Recommended when needed; it is hard to separate any risks of the steroid from risks of the severe asthma being treated. |
| Biologics | Registry data for omalizumab did not show a significant increase in major malformations; the review advises against starting it during pregnancy. |
A preconception asthma checkup
The 2024 review notes that asthma control should be assessed at every preconception visit, and that good control before conception is linked to better outcomes. Here is what a useful visit can cover:
- How often you use your rescue inhaler, and how often symptoms wake you at night.
- Your inhalers — ask someone to watch your technique. If it is off, that is one of the easiest things to fix.
- Your written asthma action plan, or a request for one.
- A baseline lung function test (spirometry) if you have not had one recently. U.S. asthma-in-pregnancy guidance recommends baseline spirometry, with spirometry or peak flow at follow-up.
- Known triggers at home and work, including smoke exposure.
- Every other medication you take, including allergy treatments.
A few cross-condition notes: if you also have high blood pressure, labetalol — a common pregnancy blood pressure medicine — is generally avoided in people with asthma, so mention your asthma to whoever manages your blood pressure (see chronic high blood pressure before pregnancy). If you snore heavily or wake unrefreshed, sleep apnea can overlap with asthma symptoms; see sleep apnea and fertility.
The rest of preconception care — folic acid, vaccines, and other medications — is covered in our TTC checklist.
The home and the household
Asthma control is partly about the environment you sleep and breathe in. If a partner or housemate smokes or vapes, trying to conceive is a natural moment to make the home smoke-free — which also helps the partner’s own health. Some people find that a shared plan for cleaning, pets, and bedroom triggers is easier to keep than solo effort.
If you work around fumes, dusts, or chemicals that bother your breathing, our guide to workplace exposures while trying to conceive covers how to raise it with occupational health.
During pregnancy: what to expect
- Change is normal. Because roughly a third of people worsen, it helps to know your early warning signs and your action-plan steps before you need them.
- Flares deserve prompt care. The CHEST Physician review reports that 20% of pregnant people with asthma needed medical intervention for a flare in one systematic review. Treating a flare quickly — including with oral steroids when needed — protects both of you.
- Your obstetric team needs to know. Tell them about your asthma and which medicines you use, so your care is coordinated.
- Breathlessness has more than one cause. Some breathlessness is normal in pregnancy, but do not assume new or worsening symptoms are “just pregnancy” — check your action plan and call if you are unsure.
The human side: the inhaler guilt
There is also a quieter kind of stress: noticing every wheeze and wondering whether it matters for a pregnancy that has not happened yet. A written action plan helps here, because it turns vague worry into clear steps — what to do in the green, yellow, and red zones, and when to call. Partners can learn the plan too, which makes it easier to ask for help at night instead of waiting until morning.
A lot of people quietly feel that the “purest” pregnancy is one with no medicines at all. With asthma, that instinct works against you. Your controller inhaler delivers a small, local dose to your lungs, and the evidence on it is reassuring; uncontrolled asthma means less oxygen on bad days, more oral steroids, and more emergency visits. Taking your preventer every day while you try to conceive is not a compromise. It is part of a healthy pregnancy plan.
Frequently asked questions
Can asthma make it harder to get pregnant?
Most people with asthma conceive without problems. One large study found that people using only rescue inhalers took about 20% longer to conceive, while those using preventer inhalers conceived as quickly as people without asthma, which suggests good control matters.
Is it safe to use my asthma inhaler while trying to conceive and during pregnancy?
Global asthma guidance advises continuing asthma medicines during pregnancy. Reviews report that inhaled corticosteroids and albuterol have not been linked to increased malformation risk, and that uncontrolled asthma carries more risk than the medicines.
Will my asthma get worse in pregnancy?
It is unpredictable. About a third of people get worse, a third stay the same, and a third improve, and the pattern often repeats in later pregnancies. Having an updated action plan helps.
Should I switch inhalers before getting pregnant?
Not necessarily. Budesonide has the most pregnancy data, but reviews note that someone well controlled on another inhaled steroid may continue it. Ask your clinician before changing anything.
Can I take oral steroids for an asthma flare while trying to conceive or pregnant?
Reviews of asthma in pregnancy recommend oral steroids when they are needed for a flare, noting it is hard to separate any steroid risks from the risks of severe asthma itself. Your clinician will weigh this with you.
What should I do if I have an asthma flare while pregnant?
Follow your action plan and contact your clinician promptly. Treating flares quickly, including with oral steroids when needed, is recommended because flares themselves are linked to pregnancy complications.
Sources & guidance
- Lab Manager: Asthma medication linked to infertility in women (summary of Grzeskowiak et al., European Respiratory Journal, SCOPE cohort)
- CHEST Physician / The Hospitalist: Maternal asthma — management strategies
- Javorac J, et al. Breathing for Two: Asthma Management, Treatment, and Safety of Pharmacological Therapy during Pregnancy. Medicines 2024;11(7):18
- American Family Physician: ACOG Practice Bulletin on chronic hypertension (labetalol cautions)