Exposure to higher temperatures in pregnancy may drive postpartum depression risk

Key takeaways:

• Exposure to higher temperature in pregnancy and postpartum may raise postpartum depression risk.
• Targeted interventions may benefit mothers exposed to higher temperatures.

Exposure to higher ambient temperatures during pregnancy and the postpartum period was associated with increased risk for postpartum depression, highlighting the potential impact of climate change on maternal mental health, data show.

“Health care professionals should be aware of the potential increased risk for postpartum depression associated with environmental stressors such as higher temperature, especially as climate change leads to more frequent heat waves,” Jun Wu, PhD, professor in the department of environmental and occupational health at the UC Irvine Joe C. Wen School of Population and Public Health, told Healio. “This may inform screening practices and preventive interventions for at-risk women.”

For the retrospective study, researchers analyzed electronic health records from 46,114 postpartum depression (PPD) cases among 429,839 pregnancies from Kaiser Permanente Southern California from 2008-2018. Researchers examined historical daily ambient temperatures and linked those to participants’ residential address at delivery. Researchers calculated PPD temperature exposures using various temperature metrics from delivery to PPD diagnosis date and estimate the association between temperature exposure and time to PPD.

The findings were published in Environmental Health Perspectives.

Jun Wu

Researchers found that PPD risk was positively associated with exposure to higher mean temperature (adjusted OR per interquartile range increment, 1.07; 95% CI, 1.05-1.09) and diurnal temperature range (aOR = 1.08; 95% CI, 1.06-1.1), with stronger associations for maximum compared with minimum temperature.

Compared with white women, temperature-related PPD risks were greater for Black, Asian and Hispanic mothers. Mothers exposed to higher levels of air pollution, less air conditioning or fewer green spaces also experienced greater effects of temperature on PPD, according to researchers.

Wu said more work is needed to investigate the biological mechanisms linking temperature exposure to PPD, the impacts of temperature on maternal mental health in diverse geographic regions, and for factors that may mitigate the risk of high temperature exposure on maternal mental health, such as climate adaptation strategies and access to green spaces.

“We must examine potential interventions to reduce the effects of heat exposure on maternal mental health, including both individual-level and community-level approaches,” Wu told Healio.

For more information:

Jun Wu, PhD, can be reached at junwu@hs.uci.edu.