Extreme Temperature and Adverse Birth Outcomes for Black and White Women in North Carolina

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. Consequently, they offer differing conclusions on the critical exposure window during gestation, and rarely acknowledge racial disparities in their outcomes. Using North Carolina birth certificate data from 2011-2020, this study evaluates the relationship between extreme cold and heat temperature exposure and adverse birth outcomes for Black and white women at four points during gestation. Various definitions (ex. ambient temperature, heat index, and wet-bulb globe temperature), thresholds (ex. 1^st percentile, 99^th percentile), and extrema (ex. maximum temperature, mean temperature, minimum temperature) of extreme temperature were explored. The relationships were strongest when exposure to the most extreme temperatures occurred cumulatively across the third trimester.