Association of maternal exposure to ambient particulate pollution with incident spontaneous pregnancy loss

Huiyu Wang; Jiajianghui Li; Hengyi Liu; Fuyu Guo; Tao Xue; Tianjia Guan; Jiwei Li

doi:10.1016/j.ecoenv.2021.112653

Association of maternal exposure to ambient particulate pollution with incident spontaneous pregnancy loss

Ecotoxicol Environ Saf. 2021 Aug 16:224:112653. doi: 10.1016/j.ecoenv.2021.112653. Online ahead of print.

Authors

Huiyu Wang¹, Jiajianghui Li¹, Hengyi Liu¹, Fuyu Guo¹, Tao Xue², Tianjia Guan³, Jiwei Li⁴

Affiliations

¹ Institute of Reproductive and Child Health / Ministry of Health Key Laboratory of Reproductive Health and Department of Epidemiology and Biostatistics, School of Public Health, Peking University, Beijing 100191, China.
² Institute of Reproductive and Child Health / Ministry of Health Key Laboratory of Reproductive Health and Department of Epidemiology and Biostatistics, School of Public Health, Peking University, Beijing 100191, China. Electronic address: txue@hsc.pku.edu.cn.
³ Department of Health Policy, School of Health Policy and Management, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730, China.
⁴ College of Computer Science and Technology, Zhejiang University, Hangzhou, Zhejiang 310027, China; Shannon.AI, Beijing 100080, China.

PMID: 34411818
DOI: 10.1016/j.ecoenv.2021.112653

Abstract

Background: Maternal exposure to ambient fine particulate matter (PM_2.5) is a potential risk factor for pregnancy loss, but the extant findings are inconsistent. One reason for the inconsistency is the difficulty of distinguishing spontaneous from induced pregnancy losses, particularly in countries with planning policies.

Objective: To examine the association between maternal PM_2.5 exposure and spontaneous incident pregnancy loss in China.

Methods: A total of 18,513 women of reproductive age was recruited from Jiangsu Province, China, in 2007. Among them, 2451 women reported 2613 valid records of incident pregnancies from 2007 to 2010. We used Cox regression to link the outcomes (live birth, spontaneous pregnancy loss, or induced abortion) of those incident pregnancies with maternal PM_2.5 exposures, assessed using well-developed estimates of historical concentrations at the county level.

Results: Among the 2613 incident pregnancies, 69 spontaneous pregnancy losses, 596 induced abortions, and 1948 live births occurred. According to the adjusted model, each 10-μg/m³ increment in the average PM_2.5 concentration during pregnancy was associated with a 43.3% (95% confidence interval, 6.6-92.5%) increased probability of spontaneous pregnancy loss. Advanced maternal age, a potential competing risk factor, weakened the association between PM_2.5 and spontaneous pregnancy loss. The association was nonsignificant for unintended pregnancies.

Conclusion: Maternal PM_2.5 exposure was associated significantly with incident spontaneous pregnancy loss. Our findings provide insight into the harmful effect of air pollution on human reproduction.

Keywords: Air pollution; Cohort study; Induced abortion; Particulate matter; Spontaneous pregnancy loss.