Air pollution tied to postpartum depression

TOPLINE:

New research suggests that long-term exposure to air pollution during and after pregnancy increases the risk of postpartum depression (PPD), adding to prior research linking air pollution to mental health issues.

METHODOLOGY:

• Researchers analyzed data on 340,679 women who had singleton live births at Kaiser Permanente Southern California facilities between 2008 and 2016.
• Ambient air pollution exposures were assessed based on maternal residential addresses using monthly averages of particulate matter ≤ 2.5 mcm (PM_2.5), PM ≤ 10 mcm (PM₁₀), nitrogen dioxide, and ozone from Environmental Protection Agency monitoring stations.
• Constituents of PM_2.5 (sulfate, nitrate, ammonium, organic matter, and black carbon) were obtained from models based on satellite, ground-based monitor, and chemical transport modeling data.
• Women with an Edinburgh Postnatal Depression Scale score of at least 10 during the first 6 months postpartum were referred for further assessment, including diagnosis and treatment.

TAKEAWAY:

• A total of 25,674 women had PPD (7.5%).
• Positive associations were observed between PPD ozone (adjusted odds ratio, 1.09), PM₁₀ (aOR, 1.02), and PM_2.5 (aOR, 1.02), with no statistically significant association with nitrogen dioxide.
• Among PM_2.5 constituents, black carbon had the strongest association with PPD (OR 1.04).
• Overall, a higher risk of PPD was associated with ozone exposure during the entire pregnancy and postpartum periods and with PM exposure during the late pregnancy and postpartum periods.

IN PRACTICE:

“These findings suggest that long-term antepartum and postpartum air pollution exposure is a potentially modifiable environmental risk factor for PPD and an important public health issue to address for improved maternal mental health,” the authors wrote.

SOURCE:

The study, with first author Yi Sun, PhD, Chinese Academy of Medical Sciences and Peking Medical College, Beijing, was published online in JAMA Network Open.

LIMITATIONS:

Postpartum exposures were estimated using only maternal address at delivery, which may have led to exposure misclassification. Potential exposure misclassifications may also exist since indoor and personal exposure levels could not be estimated. Although several covariates were adjusted for, some residual or unmeasured covariates were inevitable due to data unavailability, such as psychiatric history, adverse life events, and marital status, which may affect mental health.

DISCLOSURES:

This study was supported by a grant from the National Institute of Environmental Health Sciences. The authors report no relevant financial relationships.

A version of this article first appeared on Medscape.com.