Long-term Exposure to Fine Particulate Matter and Climate factors and The Risk of Circulatory system Disease in Women with Gestational Hypertension: A Nationwide Cohort Study in South Korea.

Background: Gestational hypertension (GHTN) is a known risk factor for long-term circulatory system conditions, encompassing both cardiovascular and other vascular disorders (CSDs). Exposure to fine particulate matter (PM2.5) from air pollution and adverse climate factors may exacerbate this risk through inflammation and oxidative stress. This study investigated the associations between long-term exposure to PM2.5 and climate factors and the risk of CSD in pregnant women with GHTN. Methods: We conducted a retrospective cohort study using Korean National Health Insurance data from 2015–2019, including 307,938 first-time pregnant women after exclusions. Environmental exposures (PM₂.₅, high temperature, and atmospheric pressure) were measured during pregnancy and throughout the two-year postpartum period. GHTN and CSD outcomes were identified via ICD-10 codes. Propensity score matching (1:4) was applied, followed by logistic regression to estimate odds ratios (ORs) for CSD, stratified by GHTN status. Results: GHTN significantly increased the risk of postpartum CSD, with an OR of up to 2.78 (95% CI: 2.63–2.94) within two years after delivery. PM₂.₅ exposure was associated with increased CSD risk, increasing from an OR of 1.07 (95% CI: 1.05–1.08) during pregnancy to 1.33 (95% CI: 1.29–1.36) postpartum. High temperature and atmospheric pressure also had positive associations with CSD risk. These effects intensified with longer exposure durations and were more pronounced among women with GHTN, suggesting a potential interaction. Additionally, CSD risk varies by socioeconomic status and region. Conclusions: Both gestational hypertension and prolonged environmental exposure significantly increase the risk of postpartum circulatory system diseases. These findings highlight the importance of postpartum monitoring and targeted environmental health interventions, especially for women with hypertensive disorders during pregnancy.