Research output: Contribution to journal/Conference contribution in journal/Contribution to newspaper › Journal article › Research › peer-review
Classification of Thyroid Dysfunction in Pregnant Women Differs by Analytical Method and Type of Thyroid Function Test. / Andersen, Stine Linding; Christensen, Peter Astrup; Knøsgaard, Louise et al.
In: The Journal of clinical endocrinology and metabolism, Vol. 105, No. 11, dgaa567, 11.2020.Research output: Contribution to journal/Conference contribution in journal/Contribution to newspaper › Journal article › Research › peer-review
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TY - JOUR
T1 - Classification of Thyroid Dysfunction in Pregnant Women Differs by Analytical Method and Type of Thyroid Function Test
AU - Andersen, Stine Linding
AU - Christensen, Peter Astrup
AU - Knøsgaard, Louise
AU - Andersen, Stig
AU - Handberg, Aase
AU - Hansen, Annebirthe Bo
AU - Vestergaard, Peter
N1 - © Endocrine Society 2020. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.
PY - 2020/11
Y1 - 2020/11
N2 - CONTEXT: Physiological alterations challenge the assessment of maternal thyroid function in pregnancy. It remains uncertain how the reference ranges vary by week of pregnancy, and how the classification of disease varies by analytical method and type of thyroid function test.DESIGN: Serum samples from Danish pregnant women (n = 6282) were used for the measurement of thyrotropin (TSH), total and free thyroxine (T4), total and free 3,5,3'-triiodothyronine (T3), and T-uptake using "Method A" (Cobas 8000, Roche Diagnostics). TSH and free T4 were also measured using "Method B" (ADVIA Centaur XP, Siemens Healthineers).MAIN OUTCOME MEASURES: Pregnancy week- and method-specific reference ranges were established among thyroid antibody-negative women (n = 4612). The reference ranges were used to classify maternal thyroid function, and results were compared by analytical method and type of thyroid function test.RESULTS: The reference ranges for TSH showed a gradual decrease during pregnancy weeks 4 to 14, a gradual increase was observed for total T4, total T3, and T-uptake, whereas free T4 and free T3 showed less variation. When TSH and free T4 were used, Method A classified 935 (14.9%) with abnormal thyroid function, Method B a total of 903 (14.4%), and the methods agreed on 554 individuals. When TSH and total T4 were used, 947 (15.1%) were classified with abnormal thyroid function, and classifications by either total T4 or free T4 agreed on 584 individuals.CONCLUSIONS: Even when pregnancy week- and method-specific reference ranges were established, the classification of maternal thyroid dysfunction varied considerably by analytical method and type of thyroid function test.
AB - CONTEXT: Physiological alterations challenge the assessment of maternal thyroid function in pregnancy. It remains uncertain how the reference ranges vary by week of pregnancy, and how the classification of disease varies by analytical method and type of thyroid function test.DESIGN: Serum samples from Danish pregnant women (n = 6282) were used for the measurement of thyrotropin (TSH), total and free thyroxine (T4), total and free 3,5,3'-triiodothyronine (T3), and T-uptake using "Method A" (Cobas 8000, Roche Diagnostics). TSH and free T4 were also measured using "Method B" (ADVIA Centaur XP, Siemens Healthineers).MAIN OUTCOME MEASURES: Pregnancy week- and method-specific reference ranges were established among thyroid antibody-negative women (n = 4612). The reference ranges were used to classify maternal thyroid function, and results were compared by analytical method and type of thyroid function test.RESULTS: The reference ranges for TSH showed a gradual decrease during pregnancy weeks 4 to 14, a gradual increase was observed for total T4, total T3, and T-uptake, whereas free T4 and free T3 showed less variation. When TSH and free T4 were used, Method A classified 935 (14.9%) with abnormal thyroid function, Method B a total of 903 (14.4%), and the methods agreed on 554 individuals. When TSH and total T4 were used, 947 (15.1%) were classified with abnormal thyroid function, and classifications by either total T4 or free T4 agreed on 584 individuals.CONCLUSIONS: Even when pregnancy week- and method-specific reference ranges were established, the classification of maternal thyroid dysfunction varied considerably by analytical method and type of thyroid function test.
U2 - 10.1210/clinem/dgaa567
DO - 10.1210/clinem/dgaa567
M3 - Journal article
C2 - 32835377
VL - 105
JO - Journal of Clinical Endocrinology and Metabolism
JF - Journal of Clinical Endocrinology and Metabolism
SN - 0021-972X
IS - 11
M1 - dgaa567
ER -