Invited Perspective: Climate Change and Maternal Mental Health-Looking beyond High-Income Countries

Abstract

Buchwald and Boudova discuss the study by Sun et al., which makes an important contribution by addressing the gap on studies on the impact of climate change on maternal health. It presents a well-executed retrospective cohort study investigating the link between ambient temperature, air pollution exposure, and postpartum depression using a large electronic medical record dataset from CA. A great strength of the study is its multidisciplinary approach of including experts in epidemiology, obstetrics, and climate science. The authors found a statistically significant increase in the risk of postpartum depression among mothers exposed to high temperatures, with the greatest risk among those simultaneously exposed to high levels of air pollution and a lack of access to air conditioning. Their findings further broaden the evidence base of the wide-ranging negative health impacts of climate chance on mothers and infants.

Refers to https://doi.org/10.1289/EHP14783

The relationship between climate change and maternal health is an increasingly urgent issue as global temperatures rise and the frequency of climate disasters accelerates.1 Maternal and neonatal morbidity and mortality are critical public health concerns,2 and the impacts of climate change disproportionately affect women owing to socioeconomic disparities and biological vulnerabilities during pregnancy.23 Good maternal mental health is vital in ensuring the health of women and neonates. Approximately one in five women experiences a mental health condition during pregnancy or postpartum4-6 and an estimated 23% of maternal mortality in the United States is attributable to mental health.7'8 Nevertheless, few studies have examined the impact of climate on maternal mental health.

The study by Sun et al. published in this issue of Environmental Health Perspectives9 makes an important contribution by addressing this gap. It presents a well-executed retrospective cohort study investigating the link between ambient temperature, air pollution exposure, and postpartum depression using a large electronic medical record dataset from California. A great strength of the study is its multidisciplinary approach of including experts in epidemiology, obstetrics, and climate science. The authors found a statistically significant increase in the risk of postpartum depression among mothers exposed to high temperatures, with the greatest risk among those simultaneously exposed to high levels of air pollution and a lack of access to air conditioning. Their findings further broaden the evidence base of the wide-ranging negative health impacts of climate change on mothers and infants.

Sun et al. convincingly demonstrated that rising temperatures may adversely affect maternal mental health in the United States. However, to fully appreciate the detrimental effects of climate change, we need to consider low- and middle-income countries (LMICs), where the most severe consequences of climate change are occurring.10'11 The vast majority of evidence for associations between environmental stressors and adverse maternal and infant health outcomes comes from high-income countries.12 But research in LMICs is possible. Ecological studies analyzing data for LMICs from the Demographic and Health Surveys

Program (https://dhsprogram.com) have found that exposure to high temperature12'13 and air pollution14 were associated with a heightened risk of adverse birth outcomes.

Such studies are currently limited by a lack of individual-level data on birth outcomes,15 as well as a lack of ground monitoring for air pollution.14 However, these logistical challenges are not insurmountable. Political will and global investment in high-quality research and public health interventions can save lives, as evidenced by the campaign against HIV/AIDS in Africa.16 Professor Mahmoud Fathalla, the past President of the International Federation of Gynecology and Obstetrics, famously said, "Women are [not] dying because of diseases we cannot treat. They are dying because societies have yet to make the decision that their lives are worth saving."17 This statement is even more applicable in the context of climate change in LMICs.

Globally, much remains unknown about the impacts of climate change on maternal and neonatal health. Climate change is characterized by alterations not only in temperature and air pollution but also in numerous other factors, including humidity, rainy season duration, and extreme weather events. The indirect impacts of climate change-such as human migration, food insecurity, and changing patterns in vector-borne disease-additionally influence maternal and neonatal health. It is critical to conduct thoughtful epidemiological studies employing multidisciplinary techniques such as those used by Sun et al. to study the relationship between these components of climate change and women's health. Moreover, it is imperative that such studies prioritize inclusivity when assessing the global impacts of climate change to ensure that we understand the effects on the most vulnerable populations.

Sun et al. relied on numerous data sources that are uncommon or nonexistent in many LMICs; standardized screening for mental health problems and widespread installation of air pollution monitors would be needed to replicate this work in high-risk settings. The authors demonstrated that the negative effects of increasing temperature were most pronounced among populations exposed to a high preexisting burden of air pollution and a lack of air conditioning. This further highlights the intersec-tionality of climate and poverty and the need to include diverse populations in climate and health research. Based on the interactions identified by Sun et al., one can extrapolate that any effect of temperature on postpartum depression would be far worse in LMICs, where there is limited access to air conditioning and high levels of household air pollution unlike those typically seen in US populations.

We call for an expansion of research to include LMICs and the multiple facets of climate change and women's health. This will yield essential knowledge for policymakers and is a human rights issue as highlighted in the Paris Agreement.18 Sun et al. have demonstrated the feasibility of applying a rigorous epidemiological approach to the challenging intersectional nexus of climate change, pregnancy, and mental health. This is a matter not only of good science but of public health, social justice, women's rights, and human rights.

References

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