Background
Southern Africa is facing increasingly extreme temperatures due to climate change. This region is already warm and dry, but now, heatwaves are becoming more intense, and temperatures are rising at double the global rate. Recent heatwaves, like those experienced in Johannesburg, highlight the urgency of addressing this issue. These changing conditions are especially concerning for pregnant women and infants, who are highly vulnerable, particularly those living in informal or low-cost housing as described by Chersich in the IPCC 6th Assessment Report
Our research has explored how heat affects maternal and child health, with a focus on three key biological pathways:
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It can cause inflammation, which can increase the risk of illness. It can cause inflammation, which can increase the risk of illness.
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It can overwhelm the body's ability to regulate temperature, leading to heat stress.
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It can cause dehydration, which is harmful to both mother and baby.
The effects of heat vary across different stages of pregnancy, during labour, and postpartum. With the rise in heat-related health problems, it is critical to understand these pathways and develop solutions.
Aims And Objectives
The Bio-HEAT Study has two main objectives:
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Understand the Biological Impacts of Heat: We aim to discover how heat exposure during pregnancy, labour, and the postpartum period negatively impacts maternal and infant health. By studying biological processes and biomarkers, we hope to uncover the precise pathways through which heat causes harm.
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Design Protective Solutions: We aim to create models that identify the times when mothers and babies are most vulnerable to heat. Using this data, we will develop protective interventions, such as cooling and hydration solutions, to help reduce the risks during pregnancy and labour.
Methods
The study will focus on 200 high-risk pregnant women recruited from the Rahima Moosa Mother and Child Hospital in Johannesburg. These women will be enrolled between 12-14 weeks of pregnancy during a 4-5 month period starting in early spring.
Participants will attend regular check-ups at key stages of pregnancy (at 20, 24, 28, 32, 36, and 40 weeks), and after birth at 1, 3, 6, 9, and 12 months. During these visits, the following data will be collected:
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Heat Exposure: Participants will track their heat exposure between visits.
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Sleep and Activity: Using wearable devices, the study will monitor sleep quality, heart rate, and activity levels.
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Hydration: Blood and urine tests will be used to measure hydration levels throughout pregnancy.
To improve outcomes, the research team will design interventions like cooling technologies and ensure better access to drinking water during labour.
For the infants, the study will track growth, developmental milestones, and health issues such as diarrhoea.
Anticipated Impact
The Bio-HEAT Study is expected to provide vital insights into how heat affects the health of pregnant women and their newborns. This research will help guide the development of interventions to prevent heat-related health issues, improving health outcomes for mothers and children globally.
In addition, this study will provide crucial evidence on the biological mechanisms of heat-related health risks, which could be instrumental in shaping future health strategies aimed at combating the effects of climate change on maternal and child health.
The findings from this study will be significant for organisations seeking climate financing, as it will demonstrate how interventions can protect maternal and child health from the growing risks of extreme heat. By identifying the biological pathways impacted by heat, the Bio-HEAT study will provide evidence to support future health interventions and policies in the context of climate change.
Role of Wits PHR
Wits PHR plays a key role in carrying out the study in partnership with the research team at Rahima Clinical Trials. Together, they will lead data collection, analysis, and the development of heat-adaptation strategies.
Partners
The study also features contributions from renowned researchers such as Dr. Phelelani Mpangase, Prof. Michael Urban, Prof. Clive Gray and Dr. Amy Wise. This study is a collaborative project involving leading institutions, including:
Funding and Programme Acknowledgement
The Bio-HEAT Study is part of the Wellcome Trust's initiative on biological vulnerability to extreme heat in maternal and child health. It is supported by Wellcome Trust grant [227204/Z/23/Z]. For more information, visit the Wellcome Trust's programme on biological vulnerability to extreme heat.