Is maternal environmental heat exposure associated with increased risk of severe maternal morbidity?

In this cohort study with 403 602 pregnancies from 2008 to 2018 in Southern California, statistically significant associations were observed between both long- and short-term maternal heat exposure during pregnancy and increased risks of severe maternal morbidity. Maternal heat exposure during pregnancy is a potential environmental risk factor for severe maternal morbidity. In this retrospective cohort study, long- and short-term heat exposure during pregnancy was associated with higher risk of SMM. These results might have important implications for SMM prevention, particularly in a changing climate.