Temperature and the Mode of Delivery: Evidence from Ecuador

Climate change is intensifying heat exposure with implications for maternal health. While existing studies have focused primarily on the biological risks of heat during pregnancy, emerging evidence suggests that temperature shocks may affect birth timing and reshape clinical decision-making and obstetric practices with consequences for mode of delivery. This study examines how ambient temperature influences birth incidence and delivery mode in Ecuador between 2015 and 2024. We link administrative birth records from Ecuador’s National Institute of Statistics and Census with high-resolution ERA5-Land temperature data at the canton level. Using fixed-effects models that exploit day-to-day weather variation within locations, we estimate the causal effect of same-day and lagged temperature exposure on total births, cesarean deliveries, and vaginal births. Hot days (>24°C) are associated with short-run increases in births on the day of exposure and the subsequent day by about 4.8%, suggesting that births are advanced and heat reduces pregnancy length. Heat exposure also reshapes delivery mode, as temperatures >24°C reduce cesarean deliveries by roughly 1.8 percentage points. Notably, the reduction in cesarean deliveries is concentrated on the day of heat exposure, with no lagged effects, indicating that procedural responses occur contemporaneously rather than through delayed rescheduling. We do not observe substantial effects of cold exposure on birth incidence or delivery mode. These findings indicate that heat exposure reduces gestational length and affects mode of delivery possibly altering access to surgical obstetric, requiring policies that support individuals in late-stage pregnancies and maternal health care systems during heatwaves.