Biodonostia Health Research Institute, Group of Environmental Epidemiology and Child Development, 20014, San Sebastian, Spain; Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Instituto de Salud Carlos III, C/Monforte de Lemos 3-5, 28029, Madrid, Spain; Department of Preventive Medicine and Public Health, Faculty of Medicine, University of the Basque Country (UPV/EHU), 48940, Leioa, Spain.
Ministry of Health of the Basque Government, SubDirectorate for Public Health and Addictions of Gipuzkoa, 20013, San Sebastián, Spain.
Environ Res. 2021 Jun;197:111132. doi: 10.1016/j.envres.2021.111132. Epub 2021 Apr 9.
Thyroid hormones play a key role in fetal and child development. Recent studies have linked prenatal exposure to atmospheric contaminants with changes in thyroid hormone levels in newborns, but the data from the few studies that have explored this issue are inconclusive. The present study aims to assess the association of total thyroxine (TT4) levels in newborns with weekly prenatal exposure to PM2.5 and NO2 and to identify sensitivity windows to exposure to air pollution in different developmental stages.
This prospective cohort study included mother-child pairs from the INMA-Gipuzkoa project. Specifically, 463 mother-child pairs with data on PM2.5 and NO2 exposure during pregnancy and TT4 levels at birth were included. PM2.5 and NO2 levels were measured by high-volume aerosol samplers and passive samplers respectively during the women's pregnancies. TT4 levels were measured in heel-prick blood samples from infants. Data on maternal and infant covariates were gathered through questionnaires administered in the first and third trimesters of pregnancy and review of clinical records. Potential associations of PM and NO2 with TT4 levels over the entire pregnancy was assessed by linear regression models and DLMs were used to identify susceptibility windows.
The exposure of pregnant women to PM during pregnancy was positively associated with infant TT4 level at birth (β [95% CI] = 0.198 [0.091, 0.305]. DLMs identified three different sensitivity windows, one in the periconceptional period with a negative association between PM exposure and TT4 levels at birth, and a second (weeks 12-17) and a third one (weeks 31-37) with a positive association. In addition, the later the exposure, the stronger the association. In contrast, no association was observed between NO exposure and TT4 levels.
The results indicate that prenatal exposure to PM could lead to a thyroid function impairment in newborns.
甲状腺激素在胎儿和儿童发育中起着关键作用。最近的研究将产前暴露于大气污染物与新生儿甲状腺激素水平的变化联系起来，但少数探索这一问题的研究的数据尚无定论。本研究旨在评估新生儿总甲状腺素（TT4）水平与每周产前暴露于 PM2.5 和 NO2 的关系，并确定不同发育阶段暴露于空气污染的敏感窗口。
这是一项前瞻性队列研究，包括 INMA-Gipuzkoa 项目中的母婴对子。具体来说，有 463 对母婴对子的数据包括怀孕期间的 PM2.5 和 NO2 暴露以及新生儿出生时的 TT4 水平。怀孕期间通过大容量气溶胶采样器和被动采样器分别测量 PM2.5 和 NO2 水平。在婴儿足跟采血样本中测量 TT4 水平。通过在妊娠第一和第三季度进行的问卷调查和临床记录审查收集了母亲和婴儿的协变量数据。通过线性回归模型评估 PM 和 NO2 与 TT4 水平在整个孕期的潜在关联，并使用 DLMs 确定易感窗口。
孕妇怀孕期间暴露于 PM 与新生儿出生时 TT4 水平呈正相关（β[95%CI] = 0.198 [0.091, 0.305]）。DLMs 确定了三个不同的敏感窗口，一个在围孕期，PM 暴露与新生儿出生时 TT4 水平呈负相关，另一个（第 12-17 周）和第三个（第 31-37 周）呈正相关。此外，暴露时间越晚，关联越强。相比之下，NO 暴露与 TT4 水平之间没有关联。
研究结果表明，产前暴露于 PM 可能导致新生儿甲状腺功能受损。
