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.
Department of Family Planning, The Second Hospital of Tianjin Medical University, Tianjin, China.
Environ Int. 2019 May;126:422-429. doi: 10.1016/j.envint.2019.02.062. Epub 2019 Mar 2.
Experimental research suggests that fine particulate matter (PM) exposure might affect embryonic development. However, only few population-based studies have investigated the impact of maternal exposure to PM on the early pregnancy loss.
To estimate associations between clinically recognized early pregnancy loss (CREPL) and exposure to ambient PM at individual residences during peri-conception periods, with the aim to identify susceptible exposure time windows.
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 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 exposures at specific peri-conception time windows and CREPL were examined using conditional logistic regression models, adjusted for covariates.
Based on adjusted models, CREPL was significantly associated with a 10 μg/m increase in PM 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 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.
Maternal exposures to ambient PM 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.
实验研究表明，细颗粒物（PM）暴露可能会影响胚胎发育。然而，只有少数基于人群的研究调查了母体 PM 暴露对早期妊娠丢失的影响。
估计个体住所周围环境 PM 暴露与围孕期着床前后早期妊娠丢失（CREPL）之间的关联，旨在确定易感暴露时间窗口。
2017 年 7 月至 2018 年 7 月，在中国天津居住的妇女中招募了 CREPL 病例和正常早期妊娠对照组（年龄和孕次相似，在一周内就诊，共 364 对）。使用时间调整的土地利用回归模型估算了女性住所地址 10 个暴露窗口（受孕前 4 周、2 周和 1 周；受孕后第一、第二、第三和第四单周、第一和第二 2 周期间以及整个 4 周期间）的平均环境 PM 浓度。使用条件逻辑回归模型调整协变量后，检查了特定围孕期时间窗口的 PM 暴露与 CREPL 之间的关系。
基于调整后的模型，在受孕后第二周 PM 暴露增加 10μg/m 时，CREPL 显著增加（OR=1.15；95%CI：1.04，1.27；p=0.005），而其他时间窗口的影响则独立存在。CREPL 还与受孕后整个 4 周的 PM 暴露相关（OR=1.22；95%CI：1.02，1.46；p=0.027）。受孕前暴露窗口与暴露之间几乎没有关联。
受孕后关键时间窗口内母体环境 PM 暴露与 CREPL 相关，受孕后第二周可能是最脆弱的暴露窗口。未来的研究应集中在复制这些发现和发病机制上。
