BMC Public Health. 2026 Jul 6. doi: 10.1186/s12889-026-28343-8. Online ahead of print.
ABSTRACT
BACKGROUND: With the increasing frequency and intensity of extreme weather events due to climate change, heat waves have emerged as a significant public health threat. To date, the potential effect of extreme heat wave events, particularly when combined with air pollution, remains poorly understood for pregnancy outcomes among women undergoing assisted reproductive technology (ART).
METHODS: A retrospective study included 15,198 women receiving ART and 7519 fresh embryo transfer cycles between 2020 to 2022 at the Reproductive Center of West China Second University Hospital in Chengdu, China. Heat wave, a climate change indicator for extreme temperature events, was calculated based on daily temperature during the period of 85 days prior to oocyte retrieval. All environmental exposure variables, including weather and pollution, were matched geospatially to day 0 to day 85 before oocyte retrieval. Generalized linear model (GLMM) were used to assess the association between environmental exposures and ART outcomes, with secondary analysis using interaction terms between heat waves and individual pollutants.
RESULTS: Exposure to one heat wave event was positively correlated with the likelihood of becoming pregnant (+ 34.9% in univariate model and + 34.5% in multivariate model for heat wave events + 1 time) and this association was more pronounced in women under 35 years of age (+ 53.7% heat wave events + 1 time), while no statistical correlation was observed between exposure to two heat wave events and ART outcomes. Additionally, CO exhibited a significant negative association with biochemical pregnancy for women under 35 years old (-66.2% for CO + 1 mg/m3), and SO2 exhibited a significant negative association on biochemical pregnancy rate for women older than 35 years old (-6.5% for SO2 + 1 μg/m3). Results from the interaction model indicated that concurrent exposure to O3 and two heat wave events was statistical associated with clinical pregnancy (OR = 3.77).
CONCLUSIONS: Findings from this study suggest that heat waves could be an important climatic indicator that reflects the impact of extreme weather on pregnancy outcomes among women receiving ART treatment. The synergy between exposure to extreme temperatures and air pollution could be further analyzed to provide deeper insight into the environmental impact on reproductive health.
PMID:42402568 | DOI:10.1186/s12889-026-28343-8
