HIGH Horizons - Reviews on the association between heat exposure and perinatal health outcomes

Abstract

The HIGH Horizons project addresses the growing concern over the adverse effects of heat exposure on maternal and newborn health, including outcomes such as preterm birth, low birth weight, and stillbirth, and contributed to the evidence-base by conducting major literature reviews. Building on the 2020 systematic review by Chersich et al., the HIGH Horizons team conducted a first comprehensive update about the impact of heat on perinatal health outcomes (deliverable D2.6), published in Nature Medicine in November 2024. A second update, presented in this report (deliverable D2.7), was conducted in December 2024 to extend the evidence period with several months. This update notably increased representation from Asia and Africa and from lower-income settings, addressing key gaps in geographic and socioeconomic diversity. It also reaffirmed strong associations between heat exposure and adverse maternal and newborn health outcomes, particularly preterm birth, stillbirth, hypertensive disorders, and low birth weight. This last systematic review update was complemented by a scoping review which focused on the effects of heat on neonatal health and identified similar concerns such as preterm birth, low birth weight and small for gestational age. Nearly 90% of the studies in the scoping review were published post-2020, reflecting the increased interest in this research area.