Analysis dataset: High ambient temperatures in pregnancy and preterm birth risk

The repository contains the analytical datasets and supporting documentation used in the study High Ambient Temperatures in Pregnancy and Preterm Birth Risk by Pepper et al, 2026. The study examined the association between high ambient temperatures during pregnancy and preterm birth in Brazil, with the aim of identifying critical exposure windows. The repository contains: (1) Analysis dataset: The individual-level analytical dataset used in the statistical analyses, including birth outcomes, gestational age, maternal characteristics, geographic identifiers, and weekly temperature and humidity exposure metrics across pregnancy. (2) Temperature percentile dataset: For each Intermediate Geographic Region (RGINT), the dataset contains temperature values corresponding to percentiles from 0.1 to 99.9 of the baseline (1986-2005) temperature distribution. (3) Data dictionary: Documentation describing all variables included across both data sets. The analysis dataset was derived by linking publicly available data from Brazil's Live Birth Information System (Sistema de Informações Sobre Nascidos Vivos) and Mortality Information System (Sistema de Informação Sobre Mortalidade), with climatic data from the Brazilian Daily Weather Gridded Data (Xavier et al, 2022). The analysis scripts are available at https://github.com/cidacslab. Together, these files allow reproduction of the analyses presented in the study. Reference: Pepper M, Cerqueira-Silva T, Masselot P, et al. High ambient temperatures in pregnancy and preterm birth risk. JAMA Netw Open. 2026;9(11):e2644788.

Keywords

Pregnancy; Brazil