MATERNAL exposure to elevated temperatures and wider diurnal temperature variations during the postpartum period is associated with an increased risk of postpartum depression, with certain maternal and environmental factors amplifying this risk.
Postpartum depression affects a significant proportion of new mothers, influenced by a combination of biological, social, and environmental factors. While extensive research exists on these influences, the potential role of temperature exposure remains underexplored. Understanding this relationship is critical, particularly in light of climate change and increasing global temperatures, as it may inform interventions to support maternal mental health.
This retrospective cohort study utilised electronic health record data from Kaiser Permanente Southern California, encompassing 429,839 pregnancies between 2008 and 2018. Postpartum depression was assessed using the Edinburgh Postnatal Depression Scale (score ≥10) and corroborated by diagnostic codes and medication data. Daily ambient temperatures were derived from the gridMET dataset and linked to maternal residential addresses at delivery. Statistical analysis employed a discrete-time logistic regression model to evaluate the relationship between postpartum temperature exposure and postpartum depression, adjusting for various demographic and environmental factors.
Among the pregnancies analysed, 46,114 cases of postpartum depression were identified (10.73%). Increased risk was observed with higher mean temperatures (adjusted odds ratio [aOR] per interquartile range increment: 1.07; 95% CI: 1.05, 1.09) and diurnal temperature range (aOR: 1.08; 95% CI: 1.06, 1.10). Maximum temperatures posed a greater risk compared to minimum temperatures. Vulnerability was heightened among African American, Asian, and Hispanic mothers, mothers aged 25 years or older, and those living in areas with higher air pollution, lower green space, or reduced air conditioning use.
These findings highlight the importance of recognising temperature as an environmental determinant of postpartum depression. For clinical practice, integrating climate and environmental considerations into postpartum care plans could better address the needs of vulnerable populations. Future research should explore mitigation strategies, including urban planning for green spaces and improving access to cooling technologies, to protect maternal mental health in a warming climate.
Abigail Craig, EMJ
Reference
Sun Y et al. Association of Postpartum Temperature Exposure with Postpartum Depression: A Retrospective Cohort Study in Southern California. Environ Health Perspect. 2024;132(11):117004.
