Ambient Air Pollution, Preconceptional Thyrotropin Abnormalities, and the Risk of Preterm Birth: A Nationwide Chinese Cohort Study
Air pollution has been associated with preterm birth (PTB); however, evidence remains limited about preconception exposure. Additionally, it remains unknown whether air pollution and thyrotropin abnormalities may synergistically contribute to incident PTB. We conducted a nationwide cohort study of 6.1 million singleton births, based on the National Free Prepregnancy Checkups Project across 29 provinces in China, 2014-2020. We observed that interquartile range increases in particulate matter with diameters ≤2.5 and ≤10 μm, nitrogen dioxide, and sulfur dioxide during 12 weeks before conception through pregnancy were associated with increased risks of PTB, with the hazard ratios of 1.25 (95% confidence intervals [CI]: 1.24, 1.25), 1.13 (95% CI: 1.13, 1.14), 1.10 (95% CI: 1.09, 1.10), and 1.24 (95% CI: 1.24, 1.25), respectively. Participants with high air pollution exposure (>75th percentile) and abnormal thyrotropin levels (<0.37 or ≥4.88 mIU/L) showed higher risks of PTB, compared to those with low air pollution exposure (<25th percentile) and normal thyrotropin levels. Additive interactions were also identified between air pollution and thyrotropin abnormalities (relative excess risk due to interaction >0, attributable proportion due to interaction >0, and synergy index >1). Our study showed that exposure to air pollution during preconception through pregnancy was associated with increased risks of PTB and that air pollution and thyrotropin abnormalities may synergistically contribute to incident PTB. These findings highlight the importance of air pollution control and thyroid management.
Authors
- Ying Yang (ORCID: https://orcid.org/0000-0003-4443-4452)
- Xu Ma (ORCID: https://orcid.org/0000-0001-7674-3589)
- Wei Huang (ORCID: https://orcid.org/0000-0001-7098-4955)
- Xinghou He (ORCID: https://orcid.org/0009-0003-9920-4811)
- Yuan Yuan Wang (ORCID: https://orcid.org/0000-0002-2141-4056)
- Huiying Xu (ORCID: https://orcid.org/0000-0003-2953-9854)
- Enyu Zhao (ORCID: https://orcid.org/0000-0001-7165-1861)
- Xuyang Shan
- Yan Fang (ORCID: https://orcid.org/0000-0002-7783-4738)
- Xiaoming Song (ORCID: https://orcid.org/0000-0002-3318-856X)
- Chuanyu Zhao (ORCID: https://orcid.org/0000-0001-8193-1699)
- Zifa Wang (ORCID: https://orcid.org/0000-0002-7062-6012)
- Bin Zhang (ORCID: https://orcid.org/0000-0003-3172-8056)
- Mengyao Li (ORCID: https://orcid.org/0000-0002-3199-9465)
- Hongguang Zhang (ORCID: https://orcid.org/0000-0002-1504-4538)
- Long Wang (ORCID: https://orcid.org/0000-0002-2733-7370)
- Qinghong Zhang (ORCID: https://orcid.org/0000-0001-6603-7656)
- Ya Zhang (ORCID: https://orcid.org/0000-0001-5277-8525)
- Jianbin Wu (ORCID: https://orcid.org/0000-0003-3063-0743)
- Xinyi Lv (ORCID: https://orcid.org/0009-0001-0972-1395)
- Hongbing Xu (ORCID: https://orcid.org/0000-0003-2851-0793)
- Jihong Xu
- Yuan He
Institutions
- Oklahoma State Department of Health (US)
- Chinese Academy of Sciences (CN)
- Chinese Academy of Medical Sciences & Peking Union Medical College (CN)
- Peking University (CN)
- Peking Union Medical College Hospital (CN)
- NOAA Oceanic and Atmospheric Research (US)
- Institute of Public Health (AL)
- Institute of Public Health Bengaluru (IN)
- Genetic Resources Center (JP)
- Czech Academy of Sciences, Institute of Atmospheric Physics (CZ)
- Tianjin Municipal Research Institute for Family Planning (CN)
- Institute of Atmospheric Physics (CN)
- Center for Human Reproduction (US)
- Lanzhou University (CN)
Publication Details
- Journal
- Environment & Health
- Published
- 2025-10-16
- DOI
- https://doi.org/10.1021/envhealth.5c00444
- Citations
- 1
- Primary Topic
- Air Quality and Health Impacts
- Type
- article
- Field-Weighted Citation Impact
- 1.20