Pregnancy and Asthma – Information for Health Care Providers
Asthma is one of the most common illnesses that complicate pregnancy.
- Asthma may occur for the first time during pregnancy, or it may change during pregnancy; in about one-third of pregnant women asthma symptoms will worsen during pregnancy, one-third will remain the same, and one-third will improve. In any case, pregnant women with asthma need treatment to control their asthma and thus protect their health and the health of their fetus.
Uncontrolled asthma during pregnancy can produce serious maternal and fetal complications. When asthma is properly controlled, however, pregnant women with asthma can maintain a normal pregnancy with little or no increased risk to themselves or their fetuses.
- Maternal complications include preeclampsia, gestational hypertension, hyperemesis gravidarum, vaginal hemorrhage, toxemia, and induced and complicated labors.
- Fetal complications include increased risk of perinatal mortality, intrauterine growth retardation, preterm birth, low birth weight, and neonatal hypoxia.
The goals of therapy for pregnant women with asthma are to control symptoms, including nocturnal symptoms; maintain normal or near-normal pulmonary function; maintain normal activity levels, including exercise; prevent acute exacerbations of asthma; avoid any adverse effects from asthma medications; and deliver a healthy infant.
- Underestimation of asthma severity and undertreatment of exacerbations are two common errors that may lead to adverse maternal and fetal outcomes.
Asthma care should be integrated with obstetric care.
- Effective management of asthma includes ongoing management to prevent asthma exacerbations and control chronic symptoms, and early intervention to relieve acute exacerbations.
- Learn when to refer patients to an asthma specialist.
There are four integral components of effective asthma management
1. Use objective measures for assessment and monitoring.
Maternal lung function:
Pulmonary Function Testing
- Using an office spirometer in the initial assessment of all pregnant patients being evaluated for asthma, and periodically thereafter as appropriate, is recommended. The single best measure of pulmonary function for assessing the severity of asthma is Forced Expiratory Volume in 1 second (FEV1). This test measures the amount of air that can forcefully be blown out in the first second of the FVC. If this number is lower than what is considered normal, it may mean asthma.
- Peak expiratory flow rate (PEFR) may be measured with portable peak flow meters, and is recommended for people with moderate to severe asthma. Peak flow measurement may also help differentiate asthma from other causes of dyspnea during pregnancy.
Fetal evaluation is based on objective measurements made by different techniques used according to gestational age and risk factors. When women with uncontrolled or severe asthma and a non-reassuring admission test of fetal assessment or other risk factors are admitted in labor, careful fetal monitoring is essential.
- Early (12 to 20 weeks) sonography provides a benchmark for progressive fetal growth. Sequential sonographic evaluations of fetal growth are indicated in second and third trimesters if asthma is moderate or severe or if growth retardation is suspected.
- Electronic fetal heart rate monitoring and ultrasonic determinations of fetal behavior in the third trimester should be used as needed to ensure fetal well-being. For many third-trimester patients weekly fetal assessment is sufficient, but frequency should increase if fetal problems are suspected.
- Daily maternal recording of fetal activity, or "kick counts," should be encouraged.
- Immediate antepartum fetal assessment is indicated in asthma exacerbations with an incomplete or poor response to therapy or with significant maternal hypoxemia. One reasonable approach to antepartum fetal assessment is continuous electronic fetal heart rate monitoring.
2. Avoid or control asthma triggers.
The identification and control of triggers--factors that induce
airway inflammation or precipitate asthma exacerbations--are
important in controlling asthma during pregnancy. Common triggers
include dust, pet dander, and cigarette smoke. Although immunotherapy should not be started during pregnancy, ongoing immunotherapy may be continued to reduce the
response to a specifically identified allergen.
If the patient is a smoker, it is important to encourage
quitting, for the health of the baby and the mother. If the
patient is exposed to second hand smoke regularly, strategies to
avoid the smoke, and helpful information about quitting smoking
should be given.
3. Establish medication
plans for chronic management of asthma
and for managing exacerbations using preferred medications.
Chronic management of asthma
Specific therapeutic regimens must be tailored to individual
needs and circumstances. A stepwise approach to pharmacological
therapy, in which the number and frequency of medications are
increased with increasing asthma severity, permits this
flexibility. Once control of asthma is sustained for several weeks
or months, a reduction in therapy--a step down--can be carefully
considered because the aim of pharmacotherapy is to use the least
medication to maintain control. (Link to stepwise worksheet) The
known risks of uncontrolled asthma are far greater than the known
risks to the mother or fetus from asthma medications.
For asthma therapy, Albuterol is the preferred quick relief medication
and inhaled corticosteriods are the preferred treatment forlong-term
control medication. Budesonide is the preferred ICS because
more data are available on using budesonide in pregnant women.
Drugs or drug classes with potential risk to the fetus:
Brompheniramine, epinephrine, and alpha-adrenergic compounds (other than pseudoephedrine), decongestants (other than pseudoephedrine), antibiotics (tetracycline, sulfonamides, and cprofloxacine), live virus vaccines, immunotherapy (initiation or increase in doses, and iodides.
For the treatment of comorbid conditions, intranasal corticosteroids are recommended for the treatment of rhinitis.
Anticipatory or early intervention is important in treating
- Every patient needs to have a written action plan
for recognizing and responding early to signs of worsening
asthma. The action plan indicates how to increase medications
in response to decreased PEFR or increased symptoms and how to
obtain medical advice at any time.
Patients should not delay seeking medical help in the emergency
department or hospital if any of the following occur:
- therapy does not provide rapid improvement
- improvement is not sustained
- there is further deterioration
- the asthma exacerbation is severe
- the fetal kick count decreases
Managing asthma during labor and delivery
- The patient's regularly scheduled asthma
medications should be continued during labor and delivery.
Patients who have required chronic systemic corticosteroids
during pregnancy should be given hydrocortisone to treat for
possible adrenal suppression.
- The patient's PEFR may be taken upon admission to
labor and delivery and, subsequently every 12 hours, if
indicated. Asthma is often inactive during labor and delivery.
- A patient already receiving asthma medication has
a risk of dangerous drug interactions. During an asthma
exacerbation, uterine contractions are common and usually do
not progress to preterm labor. Successful treatment of the
exacerbation will usually abate the contractions. If tocolytic
therapy is necessary, care should be taken to avoid the use of
more than one type of b2-agonist. Magnesium sulfate is
recommended to treat uterine contractions if the patient is
already taking a systemic b2-agonist for her asthma.
- Narcotic analgesics that cause histamine release
should be avoided; fentanyl is a preferred agent. Lumbar
epidural analgesia reduces oxygen consumption and minute
ventilation during first and second stages of labor, which
offers patients with asthma considerable benefit. If a general
anesthetic is necessary, preanesthetic use of atropine and
glycopyrrolate may provide bronchodilatory effect. For
induction of anesthesia, ketamine is the agent of choice. Low
concentrations of halogenated anesthetics can provide
bronchodilation to the patient with asthma.
- Oxytocin is the drug of choice. Prior to term, the
use of 15 methyl prostaglandin F2-alpha should be avoided
because it may cause bronchospasm; use of prostaglandin E2
suppositories or gel has not been reported to cause
- Oxytocin is the recommended agent. If additional
agents are required, methylergonovine as well as ergonovine
should be avoided if possible because they may cause
bronchospasm. If their use is unavoidable, pretreatment with
methylprednisolone is recommended. If prostaglandin treatment
is necessary, the safest analog is E2, which is less likely to
4. Educate pregnant patients to develop a partnership in asthma management.
Open communication, joint development of a treatment plan by
the clinician and patient, and encouragement of the family's
efforts to improve prevention and treatment of the patient's
symptoms will assist in promoting maternal and fetal safety and
- It is of the greatest importance for pregnant women with asthma to understand that they are "breathing for two."
- These women need information on how to properly control and manage their asthma during pregnancy to reduce the risk to the fetus.
- Concerns of pregnant women need to be elicited and addressed.