High-Risk Pregnancy - Asthma

What is asthma?

Asthma is a chronic, inflammatory disease in which the airways become sensitive to allergens (any substance that triggers an allergic reaction). Several things happen to the airways when exposed to certain triggers:

  • The lining of the airways become swollen and inflamed.
  • The muscles that surround the airways tighten.
  • The production of mucus in increased, leading to mucus plugs.

All of these factors will cause the airways to narrow - thus, making it difficult for air to go in and out of the lungs, causing the symptoms of asthma.

What are the symptoms of asthma?

The following are the most common symptoms of asthma. However, each person may experience symptoms differently. Symptoms may include:

  • coughing (either constant or intermittently)
  • wheezing (this is a whistling sound that may be heard while breathing)
  • trouble breathing or shortness of breath while exercising
  • chest tightness
  • fatigue
  • nighttime cough
  • noisy breathing

The symptoms of asthma may resemble other problems or medical conditions. Always consult your physician for a diagnosis.

What causes asthma?

The exact cause of asthma is not completely known. It is believed to be partially inherited, but it also involves many other environmental, infectious, and chemical factors.

After a person is exposed to a certain trigger, the body releases histamine and other agents that can cause inflammation in the airways. The body also releases other factors that can cause the muscles of the airways to tighten, or become smaller. There is also an increase in mucus production that may clog the airways.

The changes that occur in asthma are believed to happen in two phases:

  1. An immediate response to the trigger leads to swelling and narrowing of the airways. This makes it initially difficult for a person to breathe.
  2. A later response, which can happen four to eight hours after the initial exposure to the allergen, leads to further inflammation of the airways and obstruction of airflow.

Asthma in pregnancy:

Asthma is a common respiratory complication occurring in about 4 percent to 8 percent of pregnant women. It is interesting that asthma may improve with pregnancy in some cases, while in others, the disease is worsened. This may also vary from one pregnancy to the next in the same woman. Asthma attacks are more likely with respiratory infections and when the medication regimen is not closely followed. There may be some risk for poor fetal growth and for preterm birth (before 37 weeks of pregnancy).

Asthma management in pregnancy:

The goals of managing asthma in pregnancy are to:

  • provide the mother and fetus with oxygen.
  • prevent asthma attacks.

Management of asthma is a cooperative effort between the woman, her physicians, and her family. Management of asthma may include:

  • prevention - avoidance of triggers to which women are sensitive, especially environmental triggers such as cigarette smoke. Careful allergen control can also help, such as dust control, especially in the bedroom.
  • medications, which may include the following:
    • bronchodilators - which help open the narrowed airways.
    • cromolyn sodium - a preventive medication that helps prevent the mast cells from releasing histamine which causes allergic symptoms.
    • salmeterol - a long-acting beta2-adrenergic receptor agonist drug that causes bronchodilation by relaxing the smooth muscle in the airways.
    • corticosteroids - acts as an anti-inflammatory agent to help prevent attacks for patients with persistent asthma and prevent symptoms on a long-term basis.

According to the Centers for Disease Control and Prevention (CDC), women with chronic lung disease should receive a flu vaccine before flu season starts. The vaccine is safe to take during pregnancy. Severe asthma that does not respond to treatment may develop into respiratory failure. Mechanical breathing machines may be necessary.

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