continue normal asthma management except ICS LABA in pregnant patients
- related: Asthma reactive airway disease
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Asthma occurs in 2% to 13% of women who are pregnant worldwide and 3% to 8% in the United States and is the most common pulmonary disease encountered during pregnancy. Since 2014, pregnancy has been listed as an identifiable independent risk factor for asthma exacerbation (AE) in the Global Initiative for Asthma guidelines. It is generally thought that the one-third rule applies when predicting the effects of pregnancy on the course of asthma—one-third of patients improve, one-third worsen, and one-third remain stable. AEs are associated with adverse maternal and infant outcomes—level of evidence (LOE) A. It is known that poorly controlled asthma can be associated with maternal and fetal morbidity and mortality, including preterm labor, spontaneous abortion, prematurity, preeclampsia, placenta previa, hemorrhage, hypertensive disorders, intrauterine growth restriction, perinatal and neonatal mortality, and low-birth-weight infants. Predictors of asthma severity in pregnancy include asthma severity before pregnancy and asthma control in previous pregnancies. Worsening may occur between weeks 14 and 36 of gestation, is often worse in weeks 14 to 24, and is less common and generally less severe during the last 4 weeks of pregnancy and during labor and delivery. Reasons for worsening asthma during pregnancy include increased gastroesophageal reflux disease, sinusitis, and allergic rhinitis; decreased adherence to asthma medication plans; and the usual asthma triggers.
In general, the management of asthma in women is similar whether they are pregnant or not and involves a guideline-based stepwise approach, with a few exceptions. One of the most notable is that it is recommended that ICS therapy should not be stopped and step-down therapy not be used during pregnancy, and the current regimen should be continued (choice A is correct). Specific guideline recommendations include the following: The advantages of actively treating asthma in pregnancy markedly outweigh any potential risks of usual controller and reliever medications—LOE A; usual doses of ICS and long-acting β-agonist (LABA) are safe—LOE A; ICS reduces the risk of AE during pregnancy—LOE A; cessation of ICS during pregnancy is a significant risk factor for AE—LOE A (choice C is incorrect); ICS should not be stopped in preparation for pregnancy or during pregnancy—LOE C; and there is a low priority for step-down until after delivery—LOE D.
General pharmacologic asthma management in pregnancy includes an as-needed short-acting β-agonist (SABA) such as albuterol for short-term relief. LABA/ICS single maintenance and reliever therapy has not been directly studied in pregnancy. Controller therapy is best initiated with ICSs. Of the ICS agents, budesonide is the one best studied in pregnancy and the only one with the previous category B rating and should be the ICS used when initiating therapy in pregnancy, but a change from another ICS in a patient whose condition is stable is not recommended (choice B is incorrect). In the escalation of therapy to achieve better asthma control, the ICS dose should be escalated before adding a LABA. The LABAs are not as well studied in pregnancy but are thought to be safe and are used in the stepwise management of asthma; formoterol is usually used and always with an ICS. The long-acting muscarinic antagonists are not recommended in pregnancy owing to lack of strong human data and some animal data showing toxicity at 40 times the human daily dose. Leukotriene modifiers can be considered as alternative therapies for mild persistent asthma or as add-on therapy to inhaled glucocorticoids. On the basis of registry data, omalizumab can be continued if used before pregnancy but should generally not be initiated. There is an ongoing mepolizumab trial with results pending. Although there are limited data regarding lactation, the recommendations are generally similar to those for pregnancy.
AEs have been reported to occur in 20% to 45% of patients who are pregnant and have asthma, with severe exacerbations in approximately 10%, with study results suggesting that risk factors include being overweight, obesity, excessive first trimester weight gain, a previous exacerbation in the 12 months before pregnancy, asthma that is more difficult to control at baseline, active smoking, and anxiety. AEs should be treated with escalation of therapy, including higher doses of ICS; addition of a LABA; and, when needed, a short course of oral corticosteroids. It should be emphasized that potential risks of systemic glucocorticoids are small compared with the substantial risk to the mother and fetus of severe uncontrolled asthma. The management of severe acute asthma exacerbations during pregnancy does not differ from that in patients who are not pregnant and includes treatment with inhaled SABA albuterol; inhaled ipratropium; oral or IV glucocorticoids; and, if necessary, IV magnesium sulfate.
Results from some newer studies suggest that one can titrate asthma medications in pregnancy on the basis of fractional exhaled nitric oxide levels and the Asthma Control Questionnaire, but this approach has not yet been incorporated into most asthma guidelines (choice D is incorrect). The usual nonpharmacologic interventions to prevent exacerbations and maintain asthma control during pregnancy are also important, including patient education, avoidance of triggers such as tobacco smoke, and close monitoring.1