Mental health and asthma control during pregnancy: investigating underlying immune mechanisms

Abstract

Background: Asthma during pregnancy has been associated with poor pregnancy outcomes such as pre-eclampsia, small for gestational age babies and preterm birth. Depression and anxiety are associated with reduced asthma control in non-pregnant individuals. This study investigated whether depression/anxiety in combination with pregnancies complicated by asthma has a negative effect on asthma control. Potential immune mechanisms that may drive worsening asthma were also investigated. Methods: One hundred and eighty-nine asthmatic women with and without depression/anxiety were followed throughout their pregnancies. Incidences of uncontrolled asthma and exacerbations were measured throughout gestation. At 18 and 30 weeks of gestation, monocyte inflammatory profile was examined using flow cytometric analysis of cell surface molecules (FACS) and peripheral blood mononuclear cell (PBMC) chemotaxis was also examined. Results: The incidence of uncontrolled asthma increased in women with depression/anxiety compared to women without depression/anxiety during pregnancy (unadjusted incidence rate ratio (IRR) 1.739, adjusted IRR 1.633, CI 1.092-2.442, p=0.017). Relative risk of experiencing uncontrolled asthma during pregnancy was also increased with depression/anxiety (unadjusted RR 1.619; adjusted RR 1.538, CI 1.114-2.122, p=0.009). There was no increase in the incidence rate ratio (unadjusted IRR 0.770; adjusted IRR 0.755, CI 0.412-1.382, p=0.362) or relative risk (unadjusted RR 0.867; adjusted RR 0.859, CI 0.496-1.489, p=0.589) of asthma exacerbations during pregnancies complicated by depression/anxiety. Asthma without depression/anxiety was associated with an increase in peripheral blood total monocyte percentage at 18 but not 30 weeks gestation when compared to asthmatic women with depression/anxiety (p=0.027). There were no changes in PBMC chemotaxis at 18 or 30 weeks gestation in pregnant women regardless of the presence of asthma or depression/anxiety. Conclusion: The presence of asthma and depression/anxiety during pregnancy is associated with an increase in uncontrolled asthma, but not a change in exacerbation risk. This increase in uncontrolled asthma in women with depression/anxiety was not a result of alterations in monocyte inflammatory profile or PBMC chemotaxis.