Poorly controlled asthma could spell trouble during pregnancy. Asthma attacks - wheezing and shortness of breath - can keep the baby from getting the oxygen it needs to grow and develop. Low oxygen can lead to an underweight baby and premature birth. Before you get pregnant, talk to your doctor about your asthma and how to best manage it throughout your pregnancy.

What effect does pregnancy have on my asthma?
In about one third of women, asthma symptoms stay the same during pregnancy. For another third, they may get a little better. But for the other third of women, the symptoms get worse, especially late in the third trimester.

How safe are asthma medications during pregnancy?
Of course, you may be concerned about taking medications while you're pregnant. But uncontrolled asthma is a bigger threat to the mother and baby than taking asthma medicine. Studies show that inhaled medications do not harm the baby during pregnancy. The two types are bronchodilators, known as rescue inhalers, and inhaled corticosteroids, also called controller medications. Both are safe during pregnancy.

Will I need to change my asthma action plan?
An asthma action plan is a set of instructions from your doctor to monitor asthma daily based on peak flow numbers and symptoms. If you already have an action plan, your doctor may want to make some changes in:

• Peak flow monitoring. A peak flow meter is a hand-held device you blow into that measures air flow out of your lungs. The personal best is the peak flow result that you have when your asthma is under good control. During pregnancy, your doctor may want to determine a new personal best. You may also need to check peak flow more often.
• Allergy treatment. Allergic rhinitis (inflamed, runny nose) can sometimes get worse during pregnancy. If you have allergies, your doctor may be more aggressive about controlling them. Common allergy triggers, such as animal dander and dust mites, can make some women sneeze and may also provoke asthma symptoms. Part of your action plan might be to wash your pet more often and to use an allergen-impermeable mattress and pillow cover. Allergy shots should not be started during pregnancy. But what if you already get allergy shots from an allergist? Then your doctor may agree that you should keep getting them, as long as the dose is carefully monitored. Ask your doctor if you should continue your allergy injections while pregnant.
• Acid reflux treatment. Also known as GERD, acid reflux is a condition that can get worse during pregnancy and trigger asthma symptoms. Your doctor may advise you to take antacids and eat more frequent smaller meals rather than fewer large ones.
• Smoking. Certainly, if you smoke, pregnancy is a wake-up call to quit. Tobacco smoke is a strong trigger for an asthma attack. Avoiding this trigger should be a vital part of any asthma action plan. Smoking also reduces oxygen to the fetus. This can lead to pre-term birth and low birth weight just like unmanaged asthma.

How often will I need to see my doctor for my asthma during pregnancy?
You need regular visits to monitor your asthma throughout pregnancy even if your symptoms are well controlled. During each prenatal visit, your doctor will check your peak flow in the office and review your daily peak flow readings that you took as part of your asthma action plan. Based on your peak flow results and symptoms, your doctor may change your asthma action plan.

Related Articles Pregnancy, Labor and Delivery for Women With Asthma Controlling and Treating Asthma in Pregnancy Information for Nursing Mothers With Asthma Who Want to Continue Breast-feeding Their Babies Asthma Medications and Pregnancy: Risks and Benefits of Inhalers and Oral Steroids

External Sources Women's Health.gov. Respiratory health.. Accessed March 12, 2009 American Academy of Allergy, Asthma & Immunology. Tips to remember: asthma and pregnancy. . Accessed March 12, 2009 National Asthma Education and Prevention Program. Managing asthma during pregnancy: recommendations for pharmacologic treatment. . Accessed March 12, 2009 Whitty JE, Dombrowski MP. Asthma during pregnancy. In: Gabbe SG, Niebyl JR, Simpson JL, eds. Obstetrics: Normal and Problem Pregnancies. 5th edition. Philadelphia, PA: Churchill Livingstone Elsevier; 2007. National Asthma Education and Prevention Program. Guidelines for the diagnosis and management of asthma. . Accessed March 12, 2009

This article was reviewed and updated 08-01-2009.