Fetal Thyroid Function, Birth Weight, and Exposure to Fine Particle Air Pollution: A Birth Cohort Study.

BACKGROUND: Thyroid hormones are critical for fetal development and growth. Whether prenatal exposure to fine particle air pollution (≤ 2.5 μm; PM2.5) affects fetal thyroid function and what the impact is on birth weight in normal healthy pregnancies have not been studied yet. OBJECTIVES: We studied the impact of third-trimester PM2.5 exposure on fetal and maternal thyroid hormones and their mediating role on birth weight. METHODS: We measured the levels of free thyroid hormones (FT3, FT4) and thyroid-stimulating hormone (TSH) in cord blood (n = 499) and maternal blood (n = 431) collected afte... Mehr ...