Exposure to extreme heat or cold temperatures in the US may increase the probability of early-term births in a dose-response" manner."

Authors

• S Rawat
• N Perkins
• E DeVilbiss
• B Scholl
• T Petty
• B Kidd
• D Mav
• U Grewal
• SD Peddada

Abstract

Preterm birth is a significant public health concern. In 2022, the Centers for Disease Control (CDC) estimated that 1 in 10 pregnancies in the United States results in a preterm birth. A growing body of animal and human evidence suggests adverse effects of excess heat during pregnancy on preterm birth. However, there remains a gap in the literature on the effects of chronic exposure to extreme temperatures (both hot and cold) during pregnancy. This study analyzes data from the Consortium on Safe Labor (CSL) study – a racial/ethnic diverse cohort of over 200,000 pregnant women (2002-2008) from different US states and regions, representing different climatic conditions, demographic (age, marital status, and race/ethnicity) and socioeconomic factors (e.g., health insurance status). Daily minimum and maximum temperature distributions are derived from the PRISM dataset for location-specific extreme cold and hot temperatures, with the exposure variable defined as the proportion of days during pregnancy exposed to extreme temperatures (>30% heat and >30% cold). After adjusting for race/ethnicity, age, and select socioeconomic covariates, we obtain odds ratios of 3.2 (3.0,3.3) for extreme heat and 4.5(4.2,4.7) for extreme cold exposures during pregnancy for early preterm birth (<34 weeks) relative to full-term birth (>=39 weeks). As the proportion of days of extreme temperature exposure increases, preterm birth rates increase in a dose-response sigmoidal shape manner. Thus, we implement a novel application of constrained statistical inference to test the dose-response hypothesis and estimate the impact of simultaneous exposure to heat and cold with an overall p-value < 0.0001.

Scientific Focus Area: Epidemiology

This page was last updated on Tuesday, August 6, 2024