title: Longitudinal evaluation of thyroid autoimmunity and function in pregnant Korean women.
abstract: BACKGROUND
  Maternal thyroid dysfunction during pregnancy has been associated with adverse outcomes for both the mother and child. For this reason, it is important to understand thyroid status in pregnant women. However, there are relatively few published studies that examine thyroid function tests (TFT) and thyroid autoimmunity in non-Western pregnant women.
  
  
  METHODS
  Serum samples were longitudinally collected throughout pregnancy from 108 Korean women. TFT, thyroid peroxidase antibodies (TPO-Ab), and thyroglobulin antibodies (Tg-Ab) testing was performed. The impact of gestational age on TPO-Ab and Tg-Ab levels was evaluated and gestational age-specific reference intervals for TFT were established in antibody negative women.
  
  
  RESULTS
  In the first trimester, TPO-Ab and Tg-Ab were positive in 13.9% and 16.7% of women, respectively. For antibody positive women, median autoantibody levels for TPO-Ab and Tg-Ab dropped from first trimester to near term (133.7-10.5 IU/mL, and 162.1-21.9 IU/mL, respectively). Antibody status influenced thyroid stimulating hormone (TSH) during the first trimester, and TSH, free T4 (FT4) and total T4 (TT4) in the early second trimester. Later in gestation, no significant differences in TFT were found based on antibody status. Gestational age-specific reference intervals for TFT were calculated in antibody negative women.
  
  
  CONCLUSIONS
  Laboratory evidence of autoimmune thyroid disease (AITD) is common in this population of pregnant Korean women. Antibody status influences TFT values in the first and early second trimester. Thyroid autoantibody status and titer change in an individual-specific manner throughout pregnancy. Gestational age-specific reference intervals should be utilized for interpretation of TFT results in pregnant women.
authors: Seong-Min
authors: SM
authors: Han
authors: Jeong Hee
authors: JH
authors: Han
authors: Jina A
authors: JA
authors: Park
authors: Frank A
authors: FA
authors: Quinn
authors: Joonseok
authors: J
authors: Park
authors: Eunsuk
authors: E
authors: Oh
mesh_terms: D000328:Adult; D001323:Autoantibodies / Q000097:blood / Q000276:immunology; D001327:Autoimmune Diseases / Q000175:diagnosis* / Q000276:immunology / Q000503:physiopathology; D015551:Autoimmunity / Q000276:immunology*; D005260:Female; D006801:Humans; D007453:Iodide Peroxidase / Q000097:blood / Q000276:immunology; D008137:Longitudinal Studies; D011247:Pregnancy; D011248:Pregnancy Complications / Q000175:diagnosis* / Q000276:immunology / Q000503:physiopathology; D056910:Republic of Korea; D013954:Thyroglobulin / Q000097:blood / Q000276:immunology; D013959:Thyroid Diseases / Q000175:diagnosis* / Q000276:immunology / Q000503:physiopathology; D013960:Thyroid Function Tests; D013961:Thyroid Gland / Q000276:immunology* / Q000502:physiology* / Q000503:physiopathology
chemical_list: D001323:Autoantibodies; D013954:Thyroglobulin; D007453:Iodide Peroxidase