Published in The Lancet Regional Health Africa, the study titled “Short-term ambient temperature exposure and stillbirth in The Gambia: a time-stratified case-crossover analysis of facility-based births,” analysed 93,565 births recorded across ten public secondary and tertiary healthcare facilities between 2013 and 2018.
Among the eligible births, researchers identified 4,816 stillbirths: 2,595 (53.9%) were recorded as fresh stillbirths and 2,221 (46.1%) as macerated stillbirths. These classifications were used as proxies for likely intrapartum and antepartum fetal deaths, respectively.
The study found that higher temperatures on the day of delivery and the preceding day were associated with higher odds of fresh stillbirth. The estimated odds ratio at high temperatures compared with median temperatures was 1.22 (95% CI 0.99 – 1.50), while the pooled estimate across individual facilities was 1.17 (95% CI 1.02 – 1.35).
The association appeared stronger at inland facilities, where the estimated odds ratio was 1.54 (95% CI 1.06 – 2.25), compared with 1.11 (95% CI 0.86 – 1.43) at coastal facilities. However, researchers noted the inland estimate was based on only three facilities and should be interpreted cautiously.
For macerated stillbirths, exposure to higher temperatures two to four days before delivery showed a more modest and uncertain association. No clear association was observed when all stillbirths were considered together.
The findings are particularly relevant as temperatures continue to rise across West Africa and the Sahel. Stillbirth remains a major public health challenge in sub-Saharan Africa, yet evidence on the link between environmental heat and stillbirth in the region remains limited.
Dr Uduak Okomo, Clinical Assistant Professor at MRCG at LSHTM said: “In hot, climate-vulnerable settings such as The Gambia, women may be giving birth in facilities where keeping maternity wards cool is challenging, particularly during the hottest periods. As extreme heat becomes more frequent, we need to think about how maternity services can remain safe and resilient.”
The researchers emphasised that the findings do not establish that heat causes stillbirth, and further research is needed to understand how high temperatures affect women in labour and delivery of care.
Dr Ana Bonell, Assistant Professor at MRC Unit The Gambia at LSHTM and co-author, said: "Climate change remains the greatest threat to human health. This study highlights yet more evidence of how extreme heat harms pregnant women and their babies."
The study was supported by LSHTM-Wellcome Trust, UNICEF The Gambia and the Natural Environment Research Council (NERC), Belmont Forum.
