The role of public health interventions in modifying associations between prenatal exposures to ambient air pollution and extreme heat with child health outcomes: A systematic review.

BACKGROUND

Exposure during pregnancy to ambient air pollution and extreme heat has been linked to adverse birth, respiratory and neurodevelopmental outcomes in offspring. Pregnancy is a sensitive developmental period during which such exposures may have lasting impacts on the offspring. However, it is unclear whether public health interventions modify these associations. This review systematically examined this evidence.

METHODS

We searched MEDLINE, Scopus, Embase, Web of Science, Global Health, Maternity and Infant Care, PubMed, CINAHL and EconLit to identify studies indexed from inception to June 2025.

RESULTS

From 31,097, we screened 15,792 studies, and 21 articles met the inclusion criteria. Included studies showed high methodological heterogeneity, and studies came mainly from China (43%) and the United States (33%). Most examined ambient air pollution (n = 17), compared with extreme heat (n = 4) and none on wildfire smoke. Public health interventions examined included residential greenness (n = 11), maternal nutrition or breastfeeding duration (n = 7), community-based healthcare (n = 2), and household air conditioning use (n = 1). Evidence for effect modification by residential greenness was suggestive for preterm birth and weak for low birth weight, term low birth weight and small-for-gestational age under air pollution, and weak for preterm birth but preliminary for low birth weight and small-for-gestational age under extreme heat. Other interventions provided preliminary evidence as each was evaluated in a single study with heterogeneous exposures and outcomes.

CONCLUSION

This review found suggestive and weak evidence that residential greenness modifies prenatal exposures and adverse birth outcomes associations. More methodologically homogeneous research, including underrepresented interventions and outcomes, is needed to strengthen the evidence base.