Key Lab of Health Technology Assessment, National Health Commission of the People's Republic of China, Fudan University, Shanghai, 200032, China; Key Laboratory of Public Health Safety, Ministry of Education, School of Public Health, Fudan University, Shanghai, 200032, China.
The Maternal and Child Healthcare Hospital of Songjiang District, Shanghai, 201600, China.
Environ Pollut. 2022 Aug 15;307:119481. doi: 10.1016/j.envpol.2022.119481. Epub 2022 May 18.
Early pregnancy is crucial for fetal growth. Maternal thyroid hormone is critical for fetal growth and can be disturbed under exogenous exposure. However, it's uncertain whether exposure to PM and inorganic constituents during early pregnancy can affect TH and fetal growth. We focused on the associations of early-pregnancy PM and inorganic constituents with fetal growth and maternal THs. PM concentration was estimated using a satellite-based spatiotemporal model. Fetal biparietal diameter (BPD), head circumference (HC), femur length (FL), and humerus length (HL) were measured by ultrasonography at median 15.6, 22.2, and 33.1 gestational weeks. Levels of 28 PM constituents were measured in a sub-group of 329 pregnancies. Maternal serum free thyroxine (fT4), free triiodothyronine, and thyroid-stimulating hormone levels were measured at 14 weeks of gestation. Mixed-effect models and multiple linear regression were applied to evaluate the associations of PM and its constituents with fetal growth measures. Mediation analysis was used to examine the mediating role of the THs. Results showed that each 10 μg/m increase in PM was associated with 0.20 mm reductions in BPD (95%CI: 0.33, -0.01), 0.27 mm decreases in FL (95%CI: 0.40, -0.13), and 0.36 decreases in HL (95%CI: 0.49, -0.23). Per 10 μg/m increment in PM was correlated with 5.82% decreases in the fT4 level (95% CI: 8.61%, -2.96%). FT4 accounted for 14.3% of PM exposure-induced change in BPD at first follow-up. Al (β = -2.91, 95%CI: 5.17, -0.66), Si (β = -1.20, 95%CI: 2.22, -0.19), K (β = -3.09, 95%CI: 5.41, -0.77), Mn (β = -47.20, 95%CI: 83.68, -10.79) and Zn (β = -3.02, 95%CI: 5.55, -0.49) were associated with decreased fetal BPD, especially in first follow-up. Zn (β = -38.12%, 95% CI: 58.52%, -8.61%) was also associated with decreased fT4 levels. Overall, early pregnancy exposure to PM and its constituents was associated with fetal growth restriction and decreased maternal fT4 levels might mediate the effect of PM.
早期妊娠对胎儿生长至关重要。母体甲状腺激素对胎儿生长至关重要，但在外源暴露下可能会受到干扰。然而，目前尚不清楚早期妊娠期间暴露于 PM 和无机成分是否会影响 TH 和胎儿生长。我们专注于早期妊娠 PM 和无机成分与胎儿生长和母体 TH 的关联。使用基于卫星的时空模型估计 PM 浓度。在妊娠中位数为 15.6、22.2 和 33.1 周时，通过超声测量胎儿双顶直径（BPD）、头围（HC）、股骨长（FL）和肱骨长（HL）。在 329 例妊娠的亚组中测量了 28 种 PM 成分的水平。在妊娠 14 周时测量了母体血清游离甲状腺素（fT4）、游离三碘甲状腺原氨酸和促甲状腺激素水平。应用混合效应模型和多元线性回归评估 PM 及其成分与胎儿生长指标的关联。中介分析用于检验 TH 的中介作用。结果表明，PM 每增加 10μg/m，BPD 减少 0.20mm（95%CI：0.33，-0.01），FL 减少 0.27mm（95%CI：0.40，-0.13），HL 减少 0.36mm（95%CI：0.49，-0.23）。PM 每增加 10μg/m，fT4 水平降低 5.82%（95%CI：8.61%，-2.96%）。Al（β=-2.91，95%CI：5.17，-0.66）、Si（β=-1.20，95%CI：2.22，-0.19）、K（β=-3.09，95%CI：5.41，-0.77）、Mn（β=-47.20，95%CI：83.68，-10.79）和 Zn（β=-3.02，95%CI：5.55，-0.49）与胎儿 BPD 降低有关，尤其是在第一次随访时。Zn（β=-38.12%，95%CI：58.52%，-8.61%）也与 fT4 水平降低有关。总的来说，早期妊娠暴露于 PM 和其成分与胎儿生长受限有关，而降低的 fT4 水平可能介导了 PM 的影响。
