Disparities of Heatwave-Related Preterm Birth in Climate Types - China, 2012-2019

An association between prenatal heatwave exposure and the risk of preterm birth was found. However, the disparities in heatwave-related preterm birth across different climate types have not been examined.

This nationwide case-crossover study investigated the association between heatwave exposure and preterm birth across different Köppen-Geiger climate types. Among pregnant women residing in the arid-desert-cold climate type, exposure to compound heatwaves was found to be associated with a significantly higher risk of preterm birth {adjusted odds ratios (AORs) ranged from 1.55 [95% confidence interval ( CI): 1.21-1.97] to 2.11 (95% CI: 1.35-3.31)}. In contrast, among pregnant women residing in the tropical monsoonal climate type, exposure to daytime-only heatwaves was associated with an increased risk of preterm birth [AORs ranged from 1.25 (95% CI: 1.03-1.51) to 1.37 (95% CI: 1.05-1.77)].

Specific interventions should be implemented in China to mitigate the risk of preterm birth related to heatwaves, particularly for pregnant women residing in arid-desert-cold and tropical monsoonal climates.