State Key Laboratory of Reproductive Medicine, School of Public Health, Nanjing Medical University, No. 101 Longmian Road, Nanjing 211166, China; Key Laboratory of Modern Toxicology of Ministry of Education, School of Public Health, Nanjing Medical University, No. 101 Longmian Road, Nanjing 211166, China.
Norwegian Institute of Public Health, Department of Child Health and Development, PO Box 222 Skøyen, N-0213 Oslo, Norway.
Environ Int. 2020 Jun;139:105696. doi: 10.1016/j.envint.2020.105696. Epub 2020 Apr 4.
China, a developing country, has a particularly serious problem with metal pollution. We evaluated the association of metal exposure during pregnancy with maternal and neonatal thyroid function, and identified the critical window for maternal metal exposure effects on maternal and neonatal thyroid functions.
The maternal urinary concentrations of mercury (Hg), cadmium (Cd), arsenic (As) and cesium (Cs) were determined in pregnant women during their first (n = 389) or third (n = 257) trimesters in a prospective cohort from 2014 to 2015 in Nanjing, China, using an inductively coupled plasma mass spectrometry (ICP-MS) instrument. Maternal serum-free thyroxine (FT4) and thyroid-stimulating hormone (TSH) were measured by electrochemiluminescent microparticle immunoassays in the second and third trimesters. Neonatal TSH levels were detected 72 h after birth.
Hg (>0.162 µg/L), Cd (>0.084 µg/L), As (>0.348 µg/L) and Cs (>0.093 µg/L) were detectable in 76.9%, 90.1%, 100% and 100% of maternal urine samples from women in the first trimester of pregnancy. In the multiple adjusted linear regression models, maternal exposures to Hg and Cd in the first trimester were positively associated with maternal TSH levels in the second trimester (P < 0.01, P = 0.02). Moreover, maternal exposures to Cd and Cs in the first trimester were positively associated with neonatal TSH levels (P = 0.04, P = 0.02). In the Bayesian kernel machine regression (BKMR) model, the results were stable and consistent with the linear regression model.
Maternal exposure to Hg, Cd and Cs in the first trimester was related to TSH levels in mothers and newborns. Efforts to identify maternal and neonatal thyroid disruptors should carefully consider the effects of exposure to these metals.
中国是一个发展中国家，金属污染问题尤为严重。本研究评估了妊娠期间金属暴露与母婴甲状腺功能的关系，并确定了母体金属暴露对母婴甲状腺功能影响的关键窗口期。
采用电感耦合等离子体质谱仪（ICP-MS）检测 2014 年至 2015 年在中国南京进行的前瞻性队列研究中孕妇首次（n=389）或第三次妊娠（n=257）期间的尿汞（Hg）、镉（Cd）、砷（As）和铯（Cs）浓度。采用电化学发光微粒子免疫分析法在妊娠第二和第三孕期测量血清游离甲状腺素（FT4）和促甲状腺激素（TSH）。新生儿出生后 72 h 检测 TSH 水平。
在妊娠早期，76.9%、90.1%、100%和 100%的孕妇尿液样本中可检测到 Hg（>0.162 µg/L）、Cd（>0.084 µg/L）、As（>0.348 µg/L）和 Cs（>0.093 µg/L）。在多重调整线性回归模型中，妊娠早期母体 Hg 和 Cd 暴露与妊娠中期母体 TSH 水平呈正相关（P<0.01，P=0.02）。此外，妊娠早期母体 Cd 和 Cs 暴露与新生儿 TSH 水平呈正相关（P=0.04，P=0.02）。在贝叶斯核机器回归（BKMR）模型中，结果稳定且与线性回归模型一致。
妊娠早期母体暴露于 Hg、Cd 和 Cs 与母亲和新生儿的 TSH 水平有关。在识别母婴甲状腺功能紊乱的因素时，应仔细考虑这些金属暴露的影响。
