Variables affecting asthma course during pregnancy

Background: The course of asthma is frequently altered by pregnancy, but the mechanisms remain undefined. Objective: The purpose of this study was to identify specific maternal or pregnancy characteristics that are related to the course of asthma during pregnancy. Methods: A secondary analysis of a previous prospective study identified 568 pregnant women whose patient-reported asthma course during pregnancy was compared with the women's usual disease course. Potential explanatory variables were compared between groups defined by their pregnancy versus usual course (better, worse, same). Results: Improvement of asthma during pregnancy was noted in 33.6%, worsening was reported in 36.3%, no change was reported in 26.4%, and the course was uncertain in 3.7%. There was a significant concordance between asthma course and course of rhinitis during pregnancy. Rhinitis improved in 51.1% of patients whose asthma improved during pregnancy and worsened in 19.8% of these women. Rhinitis worsened in 55.9% of patients whose asthma worsened during pregnancy and improved in 2.1% of these women. No significant relationships were found between gestational asthma course and maternal demographic factors, panic-fear score, smoking, maternal weight, infant birth weight, or infant sex. Conclusions: The relationship of gestational asthma course to rhinitis symptoms may have clinical and mechanistic significance. Further studies will be necessary to test this hypothesis.