Asthma during pregnancy can pose health risks for you and your baby. Know how to avoid triggers and use medication safely. By Mayo Clinic Staff

Asthma is a chronic lung condition. If you're pregnant, asthma can have an impact on your health and your baby's health. Find out what you need to know about asthma and pregnancy.

If you're effectively treating your asthma and it's well controlled during pregnancy, there's little or no risk of asthma-related complications. However, severe or poorly controlled asthma during pregnancy might increase the risk of various problems, including:

  • Oxygen deprivation for the baby
  • Morning sickness
  • Vaginal bleeding
  • High blood pressure and protein in the urine after 20 weeks of pregnancy (preeclampsia)
  • Restricted fetal growth
  • Complicated labor
  • Need for a C-section
  • Premature birth
  • Low birth weight

In extreme cases, the baby's life might be in jeopardy.

Asthma is classified into four general categories, from least to most severe. Often, pregnancy doesn't affect asthma severity. For some women, however, asthma improves during pregnancy. When this happens, the improvement is generally gradual as the pregnancy progresses. It's also possible for asthma to get worse during pregnancy, with symptoms typically increasing during week 29 to week 36 of pregnancy.

It's not clear why asthma symptoms improve in some women and worsen in others during pregnancy. However, it's possible that some women experience worse asthma symptoms late in pregnancy because they stop taking their medications after becoming pregnant. Any changes you make to your medication routine might also influence the severity of your asthma symptoms.

Any medication you take during pregnancy can affect your baby. Some concerns have been raised about the use of systemic glucocorticoids, which could cause a condition in which the baby's adrenal glands don't produce enough of certain hormones immediately after birth (neonatal adrenal insufficiency). However, most asthma medications can be safely used during pregnancy. Also, it's safer to take asthma medications during pregnancy than it is to experience asthma symptoms or an asthma attack. If you're having trouble breathing, your baby might not get enough oxygen.

If you need medication to control your asthma symptoms during pregnancy, your health care provider will prescribe the safest medication at the most appropriate dosage. Take the medication exactly as prescribed. Don't stop taking the medication or adjust the dosage on your own. Depending on the type of medication you're taking and your symptoms, your health care provider might be able to monitor your asthma control during your prenatal visits. In other cases, you might need to consult your family doctor or asthma specialist throughout the pregnancy.

If you started a course of allergy shots before pregnancy, you can continue the shots during pregnancy. However, beginning a course of allergy shots during pregnancy isn't recommended. Allergy shots can cause a dangerous allergic reaction known as anaphylaxis — especially early in the course of therapy. Anaphylaxis during pregnancy can be fatal for both mother and baby.

If you have poorly controlled or moderate to severe asthma or you're recovering from a severe asthma attack, your health care provider might recommend a series of ultrasounds starting at week 32 of pregnancy to monitor your baby's growth and activity. During an ultrasound, high-frequency sound waves are used to produce images of the baby in your uterus.

If your asthma symptoms are getting steadily worse, your health care provider might recommend electronic fetal monitoring or a biophysical profile — a prenatal test used to check on a baby's well-being. The test combines fetal heart rate monitoring and fetal ultrasound. During a biophysical profile, a baby's heart rate, breathing, movements, muscle tone and amniotic fluid level are evaluated.

Your health care provider might also recommend that you pay close attention to your baby's activity level.

If you have asthma, schedule a preconception appointment with the health care provider who'll be handling your pregnancy, as well as your family doctor, allergist, pulmonologist or other members of your health care team. They'll evaluate how well you're managing your asthma and consider any treatment changes you might need to make before pregnancy begins. Because asthma symptoms might increase during pregnancy, your health care team will closely monitor your condition.

Taking good care of yourself is the best way to take care of your baby. For example:

  • Keep your prenatal appointments. Visit your health care provider regularly throughout your pregnancy. Share any questions or concerns you might have. Staying informed can help ease anxiety, which can aggravate asthma.
  • Take your medication as prescribed. If you have concerns about the medications you're taking, consult your health care provider.
  • Avoid and control triggers. Avoid exposure to secondhand smoke and other potential irritants, such as mold, pollen, dust and animal dander. If physical activity is an asthma trigger for you, your health care provider might be able to recommend treatments to reduce your symptoms.
  • Control gastroesophageal reflux disease (GERD). GERD — a chronic digestive disease that causes acid reflux and heartburn — can worsen asthma symptoms. If you develop GERD, reduce symptoms by elevating the head of your bed, eating smaller meals, waiting at least three hours after eating before lying down and avoiding foods that seem to trigger heartburn.
  • Know what's off-limits. If you smoke, ask your health care provider to help you quit. Smoking can worsen asthma, and smoking during pregnancy can cause health problems for you and your baby.
  • Recognize warning signs. Make sure you know the early signs and symptoms that your asthma is getting worse, such as coughing, chest tightness, shortness of breath or wheezing. Talk to your health care provider, family doctor or asthma specialist about home treatments and when to seek medical help.

Most women don't experience major asthma symptoms during labor and delivery. Still, continuous fetal monitoring during labor and delivery is recommended for all women who have asthma.

If you're taking asthma medication, continue doing so during labor and delivery.

Breast-feeding is encouraged for women who have asthma — even if you take medication.

A number of factors are thought to increase a person's chances of developing asthma, including having a blood relative — such as a parent or sibling — who has asthma and having a mother who smoked while pregnant. Be sure to talk to your baby's doctor about any concerns you might have about your baby's health.

Asthma doesn't have to cause health problems for you or your baby during pregnancy. Work with your health care provider to understand how to manage your symptoms and promote a healthy pregnancy.

Apr. 27, 2012