Key Laboratory of Environment and Health, Ministry of Education & Ministry of Environmental Protection, And State Key Laboratory of Environmental Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, People's Republic of China.
Wuhan Medical & Healthcare Center for Women and Children, Wuhan, 430000, Hubei, People's Republic of China.
Environ Pollut. 2021 Sep 1;284:117133. doi: 10.1016/j.envpol.2021.117133. Epub 2021 Apr 11.
Prenatal fine particulate matter (PM) exposure has been associated with impaired offspring neurodevelopment; however, the association of PM exposure during preconception with offspring's neurodevelopment and factors responsible for this association are still unclear. This study estimated the associations of PM exposure during preconception and the first trimester with offspring neurodevelopment and evaluated whether maternal thyroid hormones mediate these associations. We recruited 1329 mother-child pairs between 2013 and 2015 in Wuhan, China. PM exposure levels of each woman during the 3 months preconception and the first trimester were estimated using land-use regression models. Offspring neurodevelopment characterized by mental developmental index (MDI) and psychomotor developmental index (PDI) were measured at 24 months of age. Maternal serum levels of free thyroxine (FT3), free triiodothyronine (FT4), and thyroid-stimulating hormone (TSH) during early pregnancy were measured of a subset of the 1329 women (551 women). Generalized estimation equation and general linear regression models were used to estimate the associations between maternal PM exposure, thyroid hormones, and offspring neurodevelopment. After adjusting for potential confounders, we found that either among all participants or the subset, PM exposure during preconception and the first trimester was negatively associated with offspring PDI. Double increment in the first trimester PM exposure was significantly associated with 3.43 and 6.48 points decrease in offspring MDI. In the subset, each doubling of PM exposure during preconception and the first trimester was significantly associated with 7.93 and 8.02 points decrease in maternal FT4 level, respectively. Increased maternal FT4, in turn, was associated with increased PDI (β = 16.69, 95% CI: 5.39, 27.99). About 7.7% (95% CI: 2.0%-19.4%) and 8.6% (95% CI: 3.0%, 22.1%) of the effect of PM exposure during preconception on offspring PDI was mediated through maternal FT4 and the FT4/FT3 ratio, respectively.
孕前细颗粒物（PM）暴露与后代神经发育受损有关；然而，孕前和孕早期 PM 暴露与后代神经发育的关系以及导致这种关系的因素尚不清楚。本研究估计了孕前和孕早期 PM 暴露与后代神经发育的关系，并评估了母体甲状腺激素是否介导了这些关系。我们于 2013 年至 2015 年在中国武汉招募了 1329 对母婴对。使用基于土地利用的回归模型估计每位女性在孕前 3 个月和孕早期的 PM 暴露水平。在 24 个月时测量后代的精神发育指数（MDI）和运动发育指数（PDI）。在 1329 名女性中（551 名女性）的一部分中测量了孕早期母体血清游离甲状腺素（FT3）、游离三碘甲状腺原氨酸（FT4）和促甲状腺激素（TSH）水平。使用广义估计方程和一般线性回归模型来估计母体 PM 暴露、甲状腺激素和后代神经发育之间的关系。在调整了潜在的混杂因素后，我们发现，无论是在所有参与者中还是在亚组中，孕前和孕早期的 PM 暴露与后代 PDI 呈负相关。孕早期 PM 暴露增加一倍与后代 MDI 降低 3.43 和 6.48 分显著相关。在亚组中，孕前和孕早期 PM 暴露每增加一倍，与母体 FT4 水平分别降低 7.93 和 8.02 分显著相关。母体 FT4 水平升高反过来又与 PDI 升高相关（β=16.69，95%CI：5.39，27.99）。孕前 PM 暴露对后代 PDI 的影响约有 7.7%（95%CI：2.0%至 19.4%）和 8.6%（95%CI：3.0%至 22.1%）是通过母体 FT4 和 FT4/FT3 比值介导的。
