The narrative surrounding increasing global temperatures and the frequency of extreme weather events is something we have become used to in recent years, and scientists have sought to define what kind of impact these extremities may be having on our global population.
One such study into the impact of extreme temperatures has revealed a correlation between extreme heat exposure during the third trimester of pregnancy and an increased risk of preterm birth.
Pre-term birth, defined as a baby being born before 37 weeks of pregnancy, is estimated to affect over 10% of births in the US and higher rates in other regions. It can result in long- and short-term health complications for new-borns and be caused by a variety of factors that are the subject of ongoing scientific research.
Objectives and Research Methods
The objective of this most recent study – undertaken by researchers at Monash University and based on data collected in Australia – was to determine whether there is an association between exposure to extreme heat during pregnancy and preterm birth.
The research was conducted into births occurring in Sydney, Australia between 2000 and 2020. In total over 1.2 million births were analysed, of which over 63,000 were considered pre-term.
Within the study, ‘extreme heat’ was defined as temperatures that were on average above the 95th percentile of recorded data and included both daytime and night-time instances of extreme heat.
Drawing Correlations
Results emerging from the study presented a strong, data-led association between extreme heat exposure during the third trimester of pregnancy and preterm birth, a correlation that was not apparent during any other trimester of pregnancy.
Not only did the study reveal the strength of the association between extreme heat and preterm birth, but it also suggested that action could be taken to reduce it. While the association was apparent in all of Sydney’s residential areas, the strength of this association declined in areas with greater numbers of trees and more greenery. In fact, the data suggested that greater numbers of greenery and tree cover could reduce the likelihood of preterm birth associated with extreme heat by almost 14% and 21% respectively.
Their findings therefore reveal both a strong association between extreme heat exposure in the third trimester and preterm birth, and also a potential way to reduce this association.
The Future of Urban Planning
Due to the quantity of births studied being so high, the results do indeed suggest a strong correlation between extreme heat exposure in the third trimester and increased risk of preterm birth, and that greater levels greenery within a pregnant woman’s residential area could reduce the association. That being said, further research is needed to confirm the findings on a global scale.
Not only do the results suggest that governments and health providers should seek to prepare for increased preterm birth rates as the planet warms, but they also underscore the importance of mitigating extreme heat and advancing green space within policy and urban planning wherever possible.
Sources
Monash University
Ye, T., et al. (2024). Heat Exposure, Preterm Birth, and the Role of Greenness in Australia. JAMA Pediatrics. doi.org/10.1001/jamapediatrics.2024.0001.
