Xu Ting, Ni Haobo, Cai Xiaoyan, Dai Tingting, Wang Lingxi, Xiao Lina, Zeng Qinghui, Yu Xiaolin, Han Lu, Guo Pi
Department of Preventive Medicine, Shantou University Medical Colleage, Shantou, China.
NHC Key Laboratory of Male Reproduction and Genetics, Guangdong Provincial Reproductive Science Institute, Guangdong Provincial Fertility Hospital, Guangzhou, China.
JMIR Public Health Surveill. 2024 Aug 2;10:e53879. doi: 10.2196/53879.
Prior research has linked exposure to particulate matter with an aerodynamic diameter of ≤2.5 μm (PM2.5) with preterm birth (PTB). However, the modulating effect of preconception thyroid stimulating hormone (TSH) levels on the relationship between PM2.5 exposure and PTB has not been investigated.
This study aimed to assess whether preconception TSH levels modulate the impact of PM2.5 exposure on PTB.
This cohort study was conducted in Guangdong, China, as a part of the National Free Pre-Pregnancy Checkups Project. PM2.5 exposure was estimated by using the inverse distance weighting method. To investigate the moderating effects of TSH levels on trimester-specific PM2.5 exposure and PTB, we used the Cox proportional hazards model. Additionally, to identify the susceptible exposure windows for weekly specific PM2.5 exposure and PTB, we built distributed lag models incorporating Cox proportional hazards models.
A total of 633,516 women who delivered between January 1, 2014, to December 31, 2019, were included. In total, 34,081 (5.4%) of them had abnormal preconception TSH levels. During the entire pregnancy, each 10-μg/m3 increase in PM2.5 was linked to elevated risks of PTB (hazard ratio [HR] 1.559, 95% CI 1.390-1.748), early PTB (HR 1.559, 95% CI 1.227-1.980), and late PTB (HR 1.571, 95% CI 1.379-1.791) among women with abnormal TSH levels. For women with normal preconception TSH levels, PM2.5 exposure during the entire pregnancy was positively associated with the risk of PTB (HR 1.345, 95% CI 1.307-1.385), early PTB (HR 1.203, 95% CI 1.126-1.285), and late PTB (HR 1.386, 95% CI 1.342-1432). The critical susceptible exposure windows were the 3rd-13th and 28th-35th gestational weeks for women with abnormal preconception TSH levels, compared to the 1st-13th and 21st-35th gestational weeks for those with normal preconception TSH levels.
PM2.5 exposure was linked with a higher PTB risk, particularly in women with abnormal preconception TSH levels. PM2.5 exposure appears to have a greater effect on pregnant women who are in the early or late stages of pregnancy.
先前的研究已将暴露于空气动力学直径≤2.5μm的颗粒物（PM2.5）与早产（PTB）联系起来。然而，孕前促甲状腺激素（TSH）水平对PM2.5暴露与PTB之间关系的调节作用尚未得到研究。
本研究旨在评估孕前TSH水平是否调节PM2.5暴露对PTB的影响。
作为国家免费孕前检查项目的一部分，本队列研究在中国广东进行。采用反向距离加权法估算PM2.5暴露。为了研究TSH水平对孕期特定阶段PM2.5暴露和PTB的调节作用，我们使用了Cox比例风险模型。此外，为了确定每周特定PM2.5暴露和PTB的易感暴露窗口，我们构建了纳入Cox比例风险模型的分布滞后模型。
纳入了2014年1月1日至2019年12月31日期间分娩的633516名妇女。其中共有34081名（5.4%）孕前TSH水平异常。在整个孕期，对于孕前TSH水平异常的女性，PM2.5每增加10μg/m³与PTB风险升高（风险比[HR]1.559，95%可信区间1.390-1.748）、早期PTB（HR 1.559，95%可信区间1.227-1.980）和晚期PTB（HR 1.571，95%可信区间1.379-1.791）相关。对于孕前TSH水平正常的女性，整个孕期的PM2.5暴露与PTB风险（HR 1.345，95%可信区间1.307-1.385）、早期PTB（HR 1.203，95%可信区间1.126-1.285）和晚期PTB（HR 1.386，95%可信区间1.342-1432）呈正相关。与孕前TSH水平正常的女性在妊娠第1-13周和第21-35周相比，孕前TSH水平异常的女性的关键易感暴露窗口是妊娠第3-13周和第28-35周。
PM2.5暴露与较高的PTB风险相关，尤其是在孕前TSH水平异常的女性中。PM2.5暴露似乎对处于妊娠早期或晚期的孕妇影响更大。
