Asthma and Pregnancy
According to statistical research, approximately 8% of pregnant women suffer from asthma. The symptoms intensity of this airway disease may increase approximately between the 24th and 36th week of pregnancy.
To maintain a good health of a woman and her future child, it is necessary to choose the right method for managing asthma, both during preparation and during pregnancy.
After a successful conceiving, the female body goes through various physiological changes that affect hormone levels and can increase the need in oxygen of the female body and the fetus.
It should be noted that the woman's chest circumference enlarges in the gestation period. However, these changes do not affect the lung function anyhow, and do not increase the frequency or intensity of the symptoms.
Reduction or increase in the severity of asthma symptoms in pregnant women occurs mainly because of hormonal imbalance in the body. Different hormones, which are produced in the body of a pregnant woman, can have different effects on lung function.
- Promote airway smooth muscle relaxation, which causes a relief of bronchial spasms and other asthma symptoms (cough, dyspnea).
- An increase in the estrogen synthesis can cause edema of the mucous membranes of the respiratory tract, which increases the recurrence risk of an acute asthma episode.
Other causes of asthma relapse in pregnant women include allergic rhinitis, sinusitis or gastroesophageal reflux. They cause additional stress in pregnant women, which can be a trigger for an asthmatic attack.
To treat or prevent these risk factors for asthma, pregnant women can take antihistamine or nasal corticosteroids. During gestation, it may be impractical to use certain anti-asthmatic drugs.
For example, Prednisone (Deltasone) or Prednisolone (Pediapred) are not recommended for use during the first trimester of pregnancy because of teratogenic risk. To relieve the symptoms of asthma in a pregnant woman, doctor may prescribe an alternative to these oral corticosteroids:
- Leukotriene modifiers: Zileuton (Zyflo).
- Inhaled corticosteroids: Budesonide (Pulmicort).
- Beta2-agonists: Salmeterol (Advair), or Formoterol (Foradil).
- Cromolyn or Cromoglicic acid (Intal).
The results of six clinical studies prove that the drugs of beta2-agonists group have the most favorable safety profile in the treatment of asthma in pregnant women.
The results of the benefits and risks evaluation for asthma pharmacotherapy confirm that the use of anti-asthmatic drugs can bring benefit to the pregnant woman and her future child. They help to control breathing better, which contributes to:
- Inflow of sufficient oxygen into the blood and the placenta.
- Significant improvement in the quality of a pregnant woman’s life.
- Assurance of a normal intrauterine development of the fetus.
Treating or preventing asthma during pregnancy helps to significantly reduce the risk or avoid such consequences of this airway disease as high blood pressure, hyperemesis gravidarum, neonatal hypoxia or pre-eclampsia.
Medications for symptomatic asthma treatment are selected individually for each woman, depending on the gestational age, the severity of this respiratory disease and the intensity of its symptoms.
The drug of choice for the treatment of mild intermittent asthma in pregnant women is inhaled Albuterol (Proventil). It differs from other anti-asthmatic drugs by short action time and a high safety profile.
This bronchodilator does not cross the placenta. For this reason, Albuterol can be used to treat asthma in pregnancy without any risk to the mother or child.
To treat mild persistent asthma, low-dose Budesonide (Pulmicort) may be given to pregnant women. In case of hypersensitivity to this medication, women can use Theophylline (Uniphyl) or Cromolyn (Intal).
- Because of the high risk of adverse reactions, pregnant woman should take precautions during a Theophylline course.
- In contrast to this anti-asthmatic drug, Cromolyn has a more favorable safety profile.
- Cromolyn refers to the least effective drugs for relieving the asthma symptoms.
For an effective management of moderate persistent asthma in pregnancy, inhaled corticosteroids are used in low doses, in combination with beta2-agonists, or in mild doses as the only anti-asthmatic drug.
Pregnant women with severe persistent asthma may be prescribed an additional course of oral corticosteroids. The results of clinical studies prove that the expected benefits for woman and fetus are much higher than the risks of any adverse reactions.
To minimize the risk of asthma exacerbation in pregnancy, women are advised to avoid risk factors and observe certain precautions, which include:
- avoiding contact with animals or their wool;
- washing blankets, mattresses and bed linen with hot water (about 55°C) at least once a week to get rid of dust mites;
- keeping the windows closed and staying in open air as short as possible during the blooming period of fruit trees or flowers - their pollen can cause allergic rhinitis;
- reducing the air humidity in rooms to about 50% and reduce the risk of mold growth.
For an effective asthma management during pregnancy, future mothers should
- Avoid breathing tobacco smoke or strong odors.
- Go through spirometry tests and/or ultrasound scans at least once a month
- Regularly titrate the dose of the anti-asthmatic drug used.