Dried Blood Spot Thyroglobulin as a Biomarker of Iodine Status in Pregnant Women

J Clin Endocrinol Metab. 2017 Jan 1;102(1):23-32. doi: 10.1210/jc.2016-2829.


Context: Thyroglobulin (Tg) could be a sensitive biomarker of iodine nutrition in pregnant women (PW). A dried blood spot (DBS) assay would simplify collection and transport in field studies.

Objectives: Our aims were to (1) establish and test a reference range for DBS-Tg in PW; (2) determine whether co-measurement of Tg antibodies (Abs) is necessary to define population iodine status.

Design, setting, and participants: Standardized cross-sectional studies of 3870 PW from 11 countries. For the DBS-Tg reference range, we included TgAb-negative PW (n = 599) from 3 countries with sufficient iodine intake.

Main outcome measures: We measured the urinary iodine concentration and DBS thyroid-stimulating hormone, total thyroxin, Tg, and TgAb.

Results: In the reference population, the median DBS-Tg was 9.2 μg/L (95% confidence interval, 8.7 to 9.8 μg/L) and was not significantly different among trimesters. The reference range was 0.3 to 43.5 μg/L. Over a range of iodine intake, the Tg concentrations were U-shaped. Within countries, the median DBS-Tg and the presence of elevated DBS-Tg did not differ significantly between all PW and PW who were TgAb-negative.

Conclusions: A median DBS-Tg of ∼10 μg/L with <3% of values ≥44 μg/L indicated population iodine sufficiency. Concurrent measurement of TgAb did not appear necessary to assess the population iodine status.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Autoantibodies / blood
  • Biomarkers / blood*
  • Cross-Sectional Studies
  • Dried Blood Spot Testing / methods*
  • Dried Blood Spot Testing / standards*
  • Female
  • Follow-Up Studies
  • Humans
  • Iodine / blood
  • Iodine / deficiency*
  • Pregnancy
  • Pregnancy Trimesters / blood*
  • Prognosis
  • Reference Values
  • Thyroglobulin / blood*
  • Young Adult


  • Autoantibodies
  • Biomarkers
  • Thyroglobulin
  • Iodine