ABSTRACT
An understanding of respiratory changes during pregnancy is of utmost importance in the evaluation of the pregnant women with asthma, a condition that affects about 4% to 8% of pregnant women (see also chap. 24 in Maternal-Fetal Evidence Based Guidelines). As in the nonpregnant patient, the diagnosis of asthma in pregnancy is based on symptoms and spirometry. Asthma in pregnancy has been defined by the National Asthma Education and Prevention Program (NAEPP) 2004 working group as mild intermittent, mild persistent, moderate persistent, or severe based on symptoms and pulmonary function tests (12). Patients with mild-to-moderate asthma generally have excellent pregnancy outcomes, and there is evidence to suggest that improved control of asthma is associated with fewer complications (10). The effect of pregnancy on asthma is variable, with prospective studies showing that some patients have improvement of asthma during pregnancy, some patients have a worsening of asthma, and others have no significant change.
