The Relationship Between Extreme Temperature at Various Heat Metrics and Preterm Birth for Black Women

Climate change has been named “the biggest health threat of the 21^st century,” with pregnant mothers and infants among the most vulnerable populations to extreme temperatures, particularly extreme heat. Previous studies that have evaluated the relationship between extreme temperatures and birth outcomes show a lack of uniformity in research design as they use varying methods of defining and measuring extreme temperatures, while also failing to address or sometimes even acknowledge racial disparities within findings. The objective of the proposed study is to examine the relationship between extreme heat and preterm birth (PTB) for Black women. A daily time series of births was derived from North Carolina birth data from 2000-2020. We applied a time-stratified case crossover design with a distributed lag non-linear model (DNLM) to examine the relationship between three heat metrics: mean ambient temperature, mean wet-bulb globe temperature, and mean universal thermal climate index. Additionally, effect modification factors such as the role of the attendant at birth, rurality, and climate region were explored. Lastly, effect mediation factors such as the role of structural racism were also analyzed. Anticipated findings are that the largest increase in PTB will be at the most extreme temperatures for each metric. Findings will shed light on the importance of not only considering but including multiple and overlapping types of environment (e.g. social, political, climate) in climate-health research to more holistically understand the interplay between climate and sociopolitical factors that impact birthing outcomes for Black women.