Ambient PM2.5 and clinically recognized early pregnancy loss: A case-control study with spatiotemporal exposure predictions

Yujuan Zhang; Jianmei Wang; Li Chen; Hua Yang; Bumei Zhang; Qina Wang; Liyuan Hu; Nan Zhang; Sverre Vedal; Fengxia Xue; Zhipeng Bai

doi:10.1016/j.envint.2019.02.062

Ambient PM_2.5 and clinically recognized early pregnancy loss: A case-control study with spatiotemporal exposure predictions

Environ Int. 2019 May:126:422-429. doi: 10.1016/j.envint.2019.02.062. Epub 2019 Mar 2.

Authors

Yujuan Zhang¹, Jianmei Wang², Li Chen³, Hua Yang⁴, Bumei Zhang², Qina Wang², Liyuan Hu³, Nan Zhang⁵, Sverre Vedal⁶, Fengxia Xue⁷, Zhipeng Bai⁸

Affiliations

¹ Department of Family Planning, The Second Hospital of Tianjin Medical University, Tianjin, China; Department of Gynecology and Obstetrics, Tianjin Medical University General Hospital, Tianjin, China; State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, China.
² Department of Family Planning, The Second Hospital of Tianjin Medical University, Tianjin, China.
³ School of Geographic and Environmental Sciences, Tianjin Normal University, Tianjin, China.
⁴ Department of Family Planning, Tianjin Central Hospital of Gynecology and Obstetrics, Tianjin, China.
⁵ State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, China.
⁶ State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, China; Department of Environmental and Occupational Health Sciences, School of Public Health, University of Washington, Seattle, WA, USA.
⁷ Department of Gynecology and Obstetrics, Tianjin Medical University General Hospital, Tianjin, China. Electronic address: xuefengxia@tmu.edu.cn.
⁸ State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, China. Electronic address: baizp@craes.org.cn.

PMID: 30836309
DOI: 10.1016/j.envint.2019.02.062

Abstract

Background: Experimental research suggests that fine particulate matter (PM_2.5) exposure might affect embryonic development. However, only few population-based studies have investigated the impact of maternal exposure to PM_2.5 on the early pregnancy loss.

Objectives: To estimate associations between clinically recognized early pregnancy loss (CREPL) and exposure to ambient PM_2.5 at individual residences during peri-conception periods, with the aim to identify susceptible exposure time windows.

Methods: CREPL cases and normal early pregnancy controls (of similar age and gravidity presenting within one week, a total of 364 pairs) were recruited between July 2017 and July 2018 among women residing in Tianjin, China. Average ambient PM_2.5 concentrations of ten exposure windows (4 weeks, 2 weeks and 1 week before conception; the first, second, third and fourth single week, the first and second 2-week periods, and the entire 4-week period after conception) at the women's residential addresses were estimated using temporally-adjusted land use regression models. Associations between PM_2.5 exposures at specific peri-conception time windows and CREPL were examined using conditional logistic regression models, adjusted for covariates.

Results: Based on adjusted models, CREPL was significantly associated with a 10 μg/m³ increase in PM_2.5 exposure during the second week after conception (OR = 1.15; 95% CI: 1.04, 1.27; p = 0.005), independent of effects at other time windows. There was also an association of CREPL with PM_2.5 during the entire 4-week period after conception (OR = 1.22; 95% CI: 1.02, 1.46; p = 0.027). There was little evidence for associations with exposure during pre-conception exposure windows.

Conclusions: Maternal exposures to ambient PM_2.5 during a critical time window following conception are associated with CREPL, with the second week after conception possibly being the exposure window of most vulnerability. Future studies should focus on replicating these findings and on pathogenic mechanisms.

Keywords: Adverse pregnancy outcomes; Air pollution; Land use regression models; Miscarriage; Particulate matter.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Abortion, Spontaneous / epidemiology*
Adult
Air Pollutants / analysis*
Case-Control Studies
China / epidemiology
Female
Humans
Maternal Exposure*
Middle Aged
Particulate Matter / analysis*
Pregnancy
Young Adult

Substances

Air Pollutants
Particulate Matter