Asthma in pregnancy =================== Asthma is present in 4%-7% of pregnant women and is the respiratory disorder most frequently complicating pregnancy.[1, 2] The course of asthma during pregnancy is variable, and asthma control may remain unchanged, or become worse or improve and return the to the prepregnancy state within 3 months after parturition.[3, 4] Overall, asthma control improves significantly in the last 4 weeks of pregnancy.3 Asthmatic pregnant women have been variably reported to have an increased risk of pregnancy-induced hypertension, pre-eclampsia, caesarian section, placenta previa and antepartum or postpartum hemorrhage.[2, 5–7] Poorly controlled asthma may affect maternal comfort and safety and pregnancy outcome for both mother and child. However, data from well-designed studies have shown that treated asthmatic women have fewer adverse infant and maternal outcomes than those without therapy.[5, 8, 9] More severe asthma requiring systemic glucocorticosteroids may increase the risk of perinatal complications, including maternal pre-eclampsia, perinatal mortality, preterm births, low-birthweight infants and hyperbilirubinemia.[1, 2, 10] The relation between these pregnancy outcomes and the severity of asthma and asthma drug use by the mother is not always clear. The pharmacologic management of asthma raises significant concerns about the risk of congenital malformation in the fetus. In the general population, there is a 2%-4% risk of major congenital malformations identified at birth; only 1% of these can be attributed specifically to medications.1 The embryo is most susceptible during organ formation, from 4 to 10 weeks following the last menstrual period. Information regarding the effects of drugs administered during pregnancy comes from animal studies, human case reports and prospective cohort studies. Animal studies showing adverse effects are hard to extrapolate to humans due to dose and species effects. Most prospective cohort studies of asthma medications during pregnancy, even when available, suffer from low statistical power, and case-control studies may be biased by retrospective study design.1 For drugs with a longer history of usage, there tends to be more data to support a lack of adverse effects. Use of most common asthma medications (β2-agonists, theophylline, cromolyn, inhaled glucocorticosteroids) during pregnancy has not been shown to be associated with increased perinatal risks including congenital malformations.[1, 10] Oral glucocorticosteroids have been associated with pre-eclampsia in several studies.[2, 10] Although no asthma medications can be considered proven safe for use during pregnancy, these drugs are used to prevent the potential direct and indirect consequences of uncontrolled asthma. The patient must be aware of the risks and benefits of appropriate asthma control and must give her informed consent to the therapeutic approach recommended during pregnancy. ## Recommendations • Avoidance of allergic and nonallergic triggering factors should be the first form of therapy for asthma during pregnancy (level III). • The patient should be informed about the background risk of drugs in pregnancy in the general population. It should be made clear that, although relatively few medications have been proved harmful during pregnancy, no asthma or allergy medication can be considered to be proved safe (level II). • Physicians should discuss with the patient the possible consequences for the mother and fetus of inadequately controlled asthma, including the impact on maternal and fetal morbidity and mortality (level II). • Physicians should discuss medication choices and the rationale for the treatment plan; they should emphasize that the treatment program is considered to entail less risk than the uncontrolled illness that could result in its absence (level II). • Treatment should take the same stepped approach as in the nonpregnant patient and may include inhaled β2-agonists, inhaled corticosteroids, ipratropium bromide, cromolyn and systemic glucocorticosteroids. Theophylline may increase nausea and reflux and is less desirable. There is significantly less information about the effects of the long-acting β2-agonists and the leukotriene inhibitors, and there is less clinical experience with these drugs than with other classes of drugs. These drugs should be used only for patients whose asthma cannot be controlled using the more studied therapies (level II). • The use of systemic glucocorticosteroids for severe asthma, especially for prolonged periods, may be associated with a greater risk of pre-eclampsia, antepartum or postpartum hemorrhage, low birth weight, preterm birth and hyperbilirubinemia (level II). • Patients requiring systemic glucocorticosteroid therapy should be considered to be in a higher risk pregnancy (level II). • Physicians should address all of the patient's questions and obtain and document the patient's concurrence with the therapeutic decisions (level IV). • Physicians should monitor and support the patient and their health care providers with respect to asthma management during the pregnancy (level IV). ## References 1. 1. Schatz M. The safety of asthma and allergy medications during pregnancy. Can J Allergy Clin Immunol 1998;3(5):242-54. 2. 2. Alexander S, Dodds L, Armson BA. 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