Thyroid antagonists and thyroid indicators in U.S. pregnant women in the Vanguard Study of the National Children's Study.

The sodium iodide-symporter (NIS) mediates uptake of iodide into thyroid follicular cells. This key step in thyroid hormone synthesis is inhibited by perchlorate, thiocyanate (SCN) and nitrate (NO3) anions. When these exposures occur during pregnancy the resulting decreases in thyroid hormones may adversely affect neurodevelopment of the human fetus.

Assessment of Exposure to VOCs among Pregnant Women in the National Children's Study.

Epidemiologic studies can measure exposure to volatile organic compounds (VOCs) using environmental samples, biomarkers, questionnaires, or observations. These different exposure assessment approaches each have advantages and disadvantages; thus, evaluating relationships is an important consideration. In the National Children's Vanguard Study from 2009 to 2010, participants completed questionnaires and data collectors observed VOC exposure sources and collected urine samples from 488 third trimester pregnant women at in-person study visits.

Success rates for consent and collection of prenatal biological specimens in an epidemiologic survey of child health.

Background: The National Children's Study (NCS) Vanguard Study began enrollment in January 2009 as an initial pilot study for a planned large-scale, longitudinal U.S. cohort study of the effect of environmental influences on child health and development, with biological and environmental sample collection conducted in seven locations from April 2009 to October 2010.

Feasibility and informative value of environmental sample collection in the National Children's Vanguard Study.

Background: Birth cohort studies provide the opportunity to advance understanding of the impact of environmental factors on childhood health and development through prospective collection of environmental samples.

Methods: We evaluated the feasibility and informative value of the environmental sample collection methodology in the initial pilot phase of the National Children's Study, a planned U.S.