/ 25 August 2022

Heat from a changing climate poses a significant risk to mothers and babies

Food Shortages In Malawi As El Nino Causes Damaging Drought

Covid, HIV, Sars and Mers are all a result of humanity’s unhealthy relationship with nature. Now, one of the most relentless consequences of that toxic relationship – the climate crisis – is posing serious new health risks in Africa. 

Severe droughts, like the one currently driving millions of people from their homes in the Horn of Africa, is only one example. The climate catastrophe will also make a mockery of existing infrastructure which is not designed to withstand mounting climate-related disasters. Floods, for example, which will probably increase in regularity and intensity, will destroy buildings, roads and bridges. This will lead to increased demand for medicine tailored specifically for disasters and will have far-reaching implications for temperature-sensitive pathogens. Malaria, for instance, will probably migrate to higher altitudes.

Plain old heat, however, might be as devastating as any other part of the unfolding catastrophe. And, according to Matthew Chersich of the Wits Reproductive Health and HIV Institute, particularly for pregnant women. We already know that extreme heat increases the risk of death from respiratory, cardiovascular and cerebrovascular conditions. Now, an emerging body of research by scholars like Chersich, who delivered his inaugural lecture at the university’s Faculty of Health Sciences on 24 August, shows that among the many things set to increase along with the planet’s temperature, are child deaths.

According to one recent study, the heat-related child mortality between 2005 and 2014 could double by 2049 on our current trajectory. If temperature increases are kept within the Paris Agreement target of 1.5°C, however, as many as 6 000 child deaths could be avoided every year in Africa. Heat poses a significant risk to mothers and babies.

Heat and health risks

Foetuses exposed to temperatures above 23°C during the first few weeks of a pregnancy are associated with higher risks of maternal hypertensive disorders, according to Chersich, while mothers exposed to warmer temperatures towards the end of their pregnancies stand higher chances of premature births and stillbirths.

The biological reasons for the impact of higher temperatures on pregnant women had been something of a mystery until recently. The work of Chersich and others now suggests, among other things, however, that higher temperatures mean increased rates of food and water-borne infections and higher endocrine activation, oxidative stress and changes in placental perfusion. All of these result in maternal and foetal inflammation that triggers labour before its time.

Chersich’s research is in large part concerned with the consequences of the seemingly narrow world that separates a few degrees during pregnancy. A foetus is about half a degree warmer than the mother, which seems insignificant until the mother starts to a run a fever and it becomes the measure of survival. 

In that ambient world of already narrow margins, pregnant women are running out of room. The planet is around 1.2°C warmer than it was before the industrial revolution. Unless there are drastic cuts to emissions, it could warm by nearly 4°C more before the end of the century.

A higher burden of risk

Whether or not the climate catastrophe will have a greater impact in populations with particular health profiles is yet to be fully determined. But Chersich believes that countries with South Africa’s burden of disease face higher risks. 

“Any additional disease and strain put you at a much higher risk,” he said. “The reduced lung capacity that comes from a tuberculosis infection, for example, or any infections that might have happened before an HIV patient started antiretroviral treatment.” 

The intersection between HIV and climate change, according to Chersich, is the next frontier of research on climate change and health.

While many questions about the relationship between climate change and maternal health remain, it is now beyond doubt that rising temperatures pose serious problems for pregnant women, said Chersich. He is also heading up a new Heat and Health African Transdisciplinary Center (HE2AT), a project based out of the Wits Health Consortium that is generating new knowledge on the impacts of heat waves and extreme heat in Africa. The project is also testing solutions to the health impacts of climate change on the continent. The urgent question now is what can be done about it. There are a number of practical interventions, some of which are being tested by Chersich and his colleagues.

What can be done

Serious changes must be made to the ways we design our built environments, for instance. The temperatures in many informal settlements are higher indoors than they are outdoors, which can be devastating for expectant mothers. Many healthcare facilities are similarly ill-equipped to provide pregnant women with cooler environments. To this end, greener infrastructure will also be crucial, as will a “new kind of health worker” who understands the risks that heat poses for the pregnant women in their care, said Chersich.

All these interventions run up against a hard financial reality, however – the health sector is not yet receiving climate funding. Funding for climate change projects in Africa is overwhelmingly skewed towards agriculture and water supply and sanitation, with some going to projects in areas like disaster preparedness and transport and storage. But some of these sectors are struggling to spend their funding. The health sector, said Chersich, has well-tested experience with implementing projects and seeing them through, hardened as it is by the experience of epidemics and pandemics like HIV and Aids.

Effective public health programmes, said Chersich, are about more than treating a disease. They are about addressing their underlying causes. Beating lung cancer, for instance, will require more than new therapies and treatments. It will mean tackling the tobacco industry. And, according to Chersich, the same will be true with climate change. Public health interventions that keep pregnant women cooler will be important but the ultimate target of our interventions should be that which is heating their environments in the first place – the fossil fuel industry.