孕期PM_(2.5)暴露致母婴甲状腺功能影响的研究进展

Research progress on effects of PM_(2.5)exposure during pregnancy on maternal and infant thyroid function

环境空气污染已成为普遍存在的全球公共卫生问题,细颗粒物(PM_(2.5))作为环境空气污染的主要成分之一,其直径小,表面积大,可以携带各种有毒物质,通过血气屏障直接进入血液循环,破坏身体的各组织和器官。有研究表明孕期PM_(2.5)暴露会破坏母婴甲状腺功能,由于胎儿甲状腺在怀孕第6周左右才开始发育,因此在妊娠早期胎儿甲状腺激素几乎完全依赖于母体,母体甲状腺激素水平对胎儿的生长发育起到至关重要的作用。当孕期PM_(2.5)暴露后,母亲和胎儿之间的“桥梁”——胎盘也会受到一定程度的影响,包括胎盘碘摄取水平的改变和胎盘组织发生氧化应激、炎症、DNA甲基化等。同时孕期PM_(2.5)暴露改变母体甲状腺激素水平和胎盘正常功能会对妊娠结局造成危害作用,如早产、胎儿低出生体重、神经功能异常等一系列不良结果。本文主要从不同孕期暴露PM_(2.5)污染对母婴甲状腺功能、胎盘功能和妊娠结局的影响进行综述,有助于在不同孕期注意PM_(2.5)暴露的危害,更好更精准保护母体及胎儿健康。

Ambient air pollution has become a widespread global public health problem.As one of the main components of ambient air pollution,fine particulate matter(PM_(2.5)),with its small diameter and large surface area,can carry a variety of toxic substances and enter the blood circulation directly through the blood-air barrier,damaging various tissues and organs of human body.Studies have shown that PM_(2.5)exposure during pregnancy can disrupt the mother’s and child’s thyroid function.Since the fetal thyroid gland does not begin to develop until around the sixth week of pregnancy,the fetal thyroid hormone is almost entirely dependent on the mother during early stages of pregnancy,and maternal thyroid hormone level play a crucial role in the growth and development of fetus.When a mother is exposed to PM_(2.5)during pregnancy,placenta,the"bridge"between mother and fetus,is also affected to some extent,including changes in placental iodine uptake and oxidative stress,inflammation,and DNA methylation in placental tissue.Exposure to PM_(2.5)during pregnancy also alters maternal thyroid hormone level and normal placental function,which can have a detrimental effect on pregnancy outcomes,such as preterm birth,low birth weight,and neurological abnormalities.This paper reviewed the effects of PM_(2.5)exposure during different trimesters on maternal and infant thyroid function,placental function,and pregnancy outcomes,aiming to provide more accurate protection of maternal and fetal health.