Maternal Asthma Linked to Postpartum Depression Risk

Lucie Blais, PhD

Among the sea of changes that women experience during pregnancy, one of the most difficult to navigate is postpartum depression (PPD). But when a new mother has asthma, a recent study found that they are at an even greater risk for developing PPD.

Around 4% to 8% of US pregnant women have asthma, according to the March of Dimes. When maternal asthma is uncontrolled, the mother is at increased risk for developing preeclampsia, premature birth, and low birthweight. The National Institute of Mental Health states that 15% of women who give birth develop PPD. The condition can emerge any time after childbirth, but typically happens between 1 week and 1 month postpartum.

Investigators of this study say that there are multiple sources of research supporting the association between asthma and depression among both men and women, but only a single study specifically evaluating a connection between PPD and asthma. However, the focus was not on maternal asthma.

The cohort for this study was selected from the QAPD (Quebec Asthma and Pregnancy Database), created to analyze the impact of asthma, asthma exacerbations and asthma medications on congenital defects. Individuals had to have at least 1 asthma diagnosis recorded in the government health insurance (RAMQ) or hospitalization data collected by the Canada’s Ministry of Health and Social Services (MED-ECHO) databases within 2 years before delivery. PPD was diagnosed using the definition provided by Statistics Canada.

Participants were selected for the study if they had deliveries in a Quebec hospital between January 1998 and March 2009, gestation age between 20-45 weeks, maternal age between 15-45 years old, and no diagnosis of chronic bronchitis, emphysema, chronic airway obstruction, tuberculosis, bronchiectasis, lung cancer, or cystic fibrosis up to 2 years before delivery.

The data collection period ran from the day of delivery and until PPD was diagnosed, death from any cause, end of follow-up period (1 year postpartum), end of study period (March 2010), or beginning of a new pregnancy.

Of the 232,577 subjects, at 1 year postpartum, PPD developed in 6.1% of women with asthma versus 2.9% of women without asthma. Women with asthma were more likely to have PPD at 1 month postpartum, (OR 1.32; 95% CI: 1.15 - 1.52) and 3 months postpartum (OR: 1.46; 95%CI: 1.33 - 1.60).

Of note, the risk of PPD was higher in asthmatic women without a history of depression at both 3 months and 1 year postpartum.

Early exposure to stress that causes glucocorticoid resistance (induces inflammation), inflammatory cytokines, and the learned helpless model of depression are some possible reasons for the link, investigators noted.

In addition, some women may stop taking asthma medication for fear of harming their baby, which can cause a domino effect of uncontrolled asthma, anxiety, and depression. Data on asthma severity and or/control was not collected in this study.

The increased risk of PPD for women without a history of depression could be due to women with asthma but no history of depression being more likely to get diagnosed with PPD than women without a history of asthma or depression.

“Women with asthma should be screened for postpartum depression and get more attention in order to detect it rapidly if present so it can be treated,” lead investigator Lucie Blais, PhD, of the University of Montreal, told MD Magazine®. “The next step for finding a causal link is to replicate the study in other populations.”

The study, “Risk of Postpartum Depression Among Women with Asthma”, was published in The Journal of Allergy and Clinical Immunology: In Practice.