Establishment of trimester-specific reference intervals for thyroid stimulating hormone and free thyroxine during pregnancy in southwest China by indirect method

Objective A series of physiological changes in thyroid function occur during pregnancy and differ from those non-pregnant women. This study aimed to establish the pregnancy-specific reference intervals of TSH and FT4 using an indirect method based on the healthy pregnant women from southwest China population. Methods Thyroid function test results which available on the Laboratory Information System (LIS) were collected from the pregnancies who visited the Obstetric Clinic or the Department of Gynecology between 1 January 2015, and 30 December 2020. We grouped the data by trimesters to establish the reference intervals (RIs) based on the clinical consensus of different levels of TSH and FT4 at different weeks of gestation. All arrangements were referenced to the document CLSI EP28-A3C. Results A total of 33,040 thyroid function test results of pregnant women, aged 31 (28,33) years were statistical analyzed. Estimated RIs for TSH and FT4 in the first, second and third trimesters corresponding to the 2.5th and 97.5th percentiles in TPOAb negative were 0.02–5.23, 0.03–5.24, 0.37–5.68 mIU/L, 11.66–20.69, 10.1–18.59, 9.85–16.86pmol/L, respectively. Conclusion This study provides trimester-specific RIs for TSH and FT4 among healthy pregnant women in southwest China which guides clinicians to diagnosis and screen for thyroid disorders in this region.

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Reference Intervals of Thyroid Hormones and Correlation of BMI with Thyroid Function in Healthy Zhuang Ethnic Pregnant Women

BioMed Research International ◽

10.1155/2018/2032413 ◽

2018 ◽

Vol 2018 ◽

pp. 1-8 ◽

Cited By ~ 1

Author(s):

Yonghong Sheng ◽

Dongping Huang ◽

Shun Liu ◽

Xuefeng Guo ◽

Jiehua Chen ◽

...

Keyword(s):

Thyroid Hormones ◽

Pregnant Women ◽

Thyroid Function ◽

Reference Intervals ◽

Thyroid Stimulating Hormone ◽

Specific Reference ◽

American Thyroid Association ◽

Reference Ranges ◽

Free Triiodothyronine ◽

Cross Sectional

Ethnic differences in the level of thyroid hormones exist among individuals. The American Thyroid Association (ATA) recommends that an institution or region should establish a specific thyroid hormone reference value for each stage of pregnancy. To date, a limited number of studies have reported the level of thyroid hormones in Chinese minorities, and the exact relationship between BMI and thyroid function in pregnant women is ill. This study was performed to establish trimester-specific reference ranges of thyroid hormones in Zhuang ethnic pregnant women and explore the role of body mass index (BMI) on thyroid function. A total of 3324 Zhuang ethnic health pregnant women were recruited in this Zhuang population-based retrospective cross-sectional study. The values of thyroid stimulating hormone (TSH), free thyroxine (FT4), and free triiodothyronine (FT3) were determined by automatic chemiluminescence immunoassay analyzer. Multivariate linear regression and binary logistic regression were constructed to evaluate the influence of BMI on the thyroid function. The established reference intervals for the serum thyroid hormones in three trimesters were as follows: TSH, 0.02–3.28, 0.03–3.22, and 0.08-3.71 mIU/L; FT4, 10.57–19.76, 10.05–19.23, and 8.96–17.75 pmol/L; FT3, 3.51–5.64, 3.42–5.42, and 2.93–5.03 pmol/L. These values were markedly lower than those provided by the manufacturers for nonpregnant adults which can potentially result in 6.10% to 19.73% misclassification in Zhuang pregnant women. Moreover, BMI was positively correlated with isolated hypothyroxinemia (OR=1.081, 95% CI=1.007–1.161), while the correlation between the BMI and subclinical hypothyroidism was not statistically significant (OR=0.991, 95% CI=0.917–1.072). This is the first study focusing on the reference ranges of thyroid hormones in Guangxi Zhuang ethnic pregnant women, which will improve the care of them in the diagnosis and treatment. We also found that high BMI was positively associated with the risk of isolated hypothyroxinemia.

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The Characteristics of Children with Abnormalities Detected in Thyroid Function Tests, and Distribution of Diagnoses

Journal of Dr Behcet Uz Children s Hospital ◽

10.5222/buchd.2020.57704 ◽

2020 ◽

Author(s):

Elif Çelik ◽

Ayşe Anık

Keyword(s):

Thyroid Function ◽

Thyroid Disease ◽

Correct Diagnosis ◽

Thyroid Function Test ◽

Hashimoto Thyroiditis ◽

Thyroid Stimulating Hormone ◽

Thyroid Function Tests ◽

Test Results ◽

Function Tests ◽

Function Test

INTRODUCTION: Thyroid function tests are among the most frequently implemented laboratory tests in primary, and secondary healthcare institutions. The aim of the present study was to investigate the demographic and clinical characteristics and final diagnosis of children referred by primary and secondary healthcare institutions with the suspicion of an abnormality in thyroid function test and/or with the initial diagnosis of specific thyroid disease. METHODS: A total of two hundred eighty-nine pediatric patients, aged between 4 and 18 years admitted to the outpatient clinics of Behçet Uz Children’s Health and Diseases Hospital between January 2018 and January 2020, were included in the study. The patient data were obtained retrospectively from the hospital records. RESULTS: A total of 66% of the patients who were included in the study were female with a median age of 12 years (8.7-14.4), while 64% of them were pubertal; and 78% of the cases were referred by secondary healthcare institutions. The most common reason for referral was isolated elevation of thyroid stimulating hormone (TSH). A total of 56% of the patients were asymptomatic at the time of admission, and thyroid function test results of 75% of them were within normal limits. When evaluated according to their final diagnoses, the children were normal/healthy (64%), diagnosed with Hashimoto thyroiditis (30%), nodular thyroid disease (3%), Graves disease (2%) and isolated increase of TSH was related to obesity in 5 patients (1%). DISCUSSION AND CONCLUSION: It is essential to evaluate children with abnormal thyroid function test results with detailed history and physical examination. Besides, the thyroid function tests should be performed with reliable and sensitive methods in standardized laboratories to reach the correct diagnosis in these children.

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Evaluation of the usefulness of a sensitive immunoradiometric assay for thyroid stimulating hormone as a first-line thyroid function test in an unselected patient population

Scandinavian Journal of Clinical and Laboratory Investigation ◽

10.3109/00365518709168893 ◽

1987 ◽

Vol 47 (3) ◽

pp. 215-221 ◽

Cited By ~ 2

Author(s):

U. -B. Ericsson ◽

P. Fernlund ◽

J. I. Thorell

Keyword(s):

Thyroid Function ◽

Patient Population ◽

Thyroid Function Test ◽

Thyroid Stimulating Hormone ◽

Immunoradiometric Assay ◽

First Line ◽

Unselected Patient ◽

Function Test ◽

Unselected Patient Population ◽

Stimulating Hormone

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Reference intervals for neonatal thyroid function tests in the first 7 days of life

Journal of Pediatric Endocrinology and Metabolism ◽

10.1515/jpem-2018-0007 ◽

2018 ◽

Vol 31 (10) ◽

pp. 1113-1116 ◽

Cited By ~ 4

Author(s):

Michelle S. Jayasuriya ◽

Kay W. Choy ◽

Lit K. Chin ◽

James Doery ◽

Alice Stewart ◽

...

Keyword(s):

Thyroid Function ◽

Medical Records ◽

Reference Intervals ◽

Thyroid Stimulating Hormone ◽

Primary Hypothyroidism ◽

Specific Reference ◽

Rapid Decline ◽

Thyroid Function Tests ◽

Accurate Identification ◽

Neonatal Hypothyroidism

Abstract Background: Prompt intervention can prevent permanent adverse neurological effects caused by neonatal hypothyroidism. Thyroid function changes rapidly in the first few days of life but well-defined age-specific reference intervals (RIs) for thyroid-stimulating hormone (TSH), free thyroxine (FT4) and free tri-iodothyronine (FT3) are not available to aid interpretation. We developed hour-based RIs using data mining. Methods: All TSH, FT4 and FT3 results with date and time of collection from neonates aged <7 days during 2005–2015 were extracted from the Monash Pathology database. Neonates with more than one episode of testing or with known primary hypothyroidism, identified by treating physicians or from medical records, were excluded from the analysis. The date and time of birth were obtained from the medical records. Results: Of the 728 neonates qualifying for the study, 569 had time of birth available. All 569 had TSH, 415 had FT4 and 146 had FT3 results. For age ≤24 h, 25–48 h, 49–72 h, 73–96 h, 97–120 h, 121–144 h and 145–168 h of life, the TSH RIs (2.5th–97.5th) (mIU/L) were 4.1–40.2, 3.2–29.6, 2.6–17.3, 2.2–14.7, 1.8–14.2, 1.4–12.7 and 1.0–8.3, respectively; the FT4 RIs (mean ± 2 standard deviation [SD]) (pmol/L) were 15.3–43.6, 14.7–53.2, 16.5–45.5, 17.8–39.4, 15.3–32.1, 14.5–32.6 and 13.9–30.9, respectively; the FT3 RIs (mean±2 SD) (pmol/L) were 5.0–9.4, 4.1–9.1, 2.8–7.8, 2.9–7.8, 3.5–7.2, 3.4–8.0 and 3.8–7.9, respectively. Conclusions: TSH and FT4 were substantially high in the first 24 h after birth followed by a rapid decline over the subsequent 168 h. Use of hour-based RIs in newborns allows for more accurate identification of neonates who are at risk of hypothyroidism.

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Discrepant thyroid-function test results by fluorescent polarization and radioimmunoassay in nonthyroidal illness.

Clinical Chemistry ◽

10.1093/clinchem/33.4.613a ◽

1987 ◽

Vol 33 (4) ◽

pp. 613-614

Author(s):

M R Winton ◽

T Stickland

Keyword(s):

Thyroid Function ◽

Thyroid Function Test ◽

Test Results ◽

Nonthyroidal Illness ◽

Function Test

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Development of Gestational Age-Specific Thyroid Function Test Reference Intervals in Four Analytic Platforms Through Multilevel Modeling

Thyroid ◽

10.1089/thy.2019.0323 ◽

2020 ◽

Vol 30 (4) ◽

pp. 598-608 ◽

Cited By ~ 1

Author(s):

Lai Yuk Yuen ◽

Michael Ho Ming Chan ◽

Daljit Singh Sahota ◽

Lydia Choi Wan Lit ◽

Chung Shun Ho ◽

...

Keyword(s):

Multilevel Modeling ◽

Thyroid Function ◽

Gestational Age ◽

Thyroid Function Test ◽

Reference Intervals ◽

Function Test

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Gestation specific reference intervals for thyroid function tests in pregnancy

Clinical Chemistry and Laboratory Medicine (CCLM) ◽

10.1515/cclm-2015-0569 ◽

2016 ◽

Vol 54 (8) ◽

Cited By ~ 6

Author(s):

Süleyman Akarsu ◽

Filiz Akbiyik ◽

Eda Karaismailoglu ◽

Zeliha Gunnur Dikmen

Keyword(s):

Pregnant Women ◽

Thyroid Function ◽

First Trimester ◽

Reference Intervals ◽

Specific Reference ◽

Thyroid Function Tests ◽

Second Trimester ◽

Third Trimester ◽

The Third ◽

Function Tests

AbstractThyroid function tests are frequently assessed during pregnancy to evaluate thyroid dysfunction or to monitor pre-existing thyroid disease. However, using non-pregnant reference intervals can lead to misclassification. International guidelines recommended that institutions should calculate their own pregnancy-specific reference intervals for free thyroxine (FT4), free triiodothyronine (FT3) and thyroid-stimulating hormone (TSH). The objective of this study is to establish gestation-specific reference intervals (GRIs) for thyroid function tests in pregnant Turkish women and to compare these with the age-matched non-pregnant women.Serum samples were collected from 220 non-pregnant women (age: 18–48), and 2460 pregnant women (age: 18–45) with 945 (39%) in the first trimester, 1120 (45%) in the second trimester, and 395 (16%) in the third trimester. TSH, FT4 and FT3 were measured using the Abbott Architect i2000SR analyzer.GRIs of TSH, FT4 and FT3 for first trimester pregnancies were 0.49–2.33 mIU/L, 10.30–18.11 pmol/L and 3.80–5.81 pmol/L, respectively. GRIs for second trimester pregnancies were 0.51–3.44 mIU/L, 10.30–18.15 pmol/L and 3.69–5.90 pmol/L. GRIs for third trimester pregnancies were 0.58–4.31 mIU/L, 10.30–17.89 pmol/L and 3.67–5.81 pmol/L. GRIs for TSH, FT4 and FT3 were different from non-pregnant normal reference intervals.TSH levels showed an increasing trend from the first trimester to the third trimester, whereas both FT4 and FT3 levels were uniform throughout gestation. GRIs may help in the diagnosis and appropriate management of thyroid dysfunction during pregnancy which will prevent both maternal and fetal complications.

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Salsalate alters thyroid function test results

Arthritis & Rheumatism ◽

10.1002/anr.1780321031 ◽

1989 ◽

Vol 32 (10) ◽

pp. 1344-1344 ◽

Cited By ~ 5

Author(s):

Robert J. McConnell

Keyword(s):

Thyroid Function ◽

Thyroid Function Test ◽

Test Results ◽

Function Test

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Specific Reference Intervals of Serum Triiodothyronine, Thyroxine, and Thyroid-stimulating Hormone in Normal Pregnant Indian Women as per Trimester

Indian Journal of Medical Biochemistry ◽

10.5005/jp-journals-10054-0012 ◽

2017 ◽

Vol 21 (1) ◽

pp. 17-21

Author(s):

Nandita Hazra ◽

Binay Mitra ◽

Reetika Pal

Keyword(s):

Thyroid Hormone ◽

Pregnant Women ◽

Reference Intervals ◽

Thyroid Stimulating Hormone ◽

Specific Reference ◽

Indian Women ◽

Hormone Levels ◽

Thyroid Hormone Levels ◽

Maternal Thyroid ◽

Stimulating Hormone

ABSTRACT Aim Maternal thyroid hormone levels during pregnancy are vital for the health of the mother as well as the developing child. Fetal growth is affected by maternal thyroid levels. Various physiological changes like alterations of thyroxine-binding globulins, human chorionic gonadotropin level, and changes in iodide metabolism affect maternal thyroid hormone levels. Therefore, reference intervals (RIs) for thyroid hormones in pregnant population require to be established separately from the general population. Materials and methods The RIs of serum triiodothyronine (T3), thyroxine (T4), and thyroid-stimulating hormone (TSH) were determined in healthy pregnant women by enzyme-linked immunosorbent assay (ELISA) technique after segregating them into three trimesters. This study was conducted in a 492-bedded zonal-level hospital. The reference population was chosen from a study population of pregnant women by strict inclusion and exclusion criteria. The assays were done by the most-commonly used, economical ELISA method employing standard kits. Tests were done using accurate and precise methods with proper quality control measures. Results The RIs were calculated from the central 95% of distribution of total T3, total T4, and TSH values located between 2.5 and 97.5 percentile values. The 0.90 confidence intervals for the upper and lower reference limits were calculated. The values thus obtained were different from those provided by the manufacturer kit literature. Conclusion It is recommended to determine one's own laboratory-specific, method-specific, trimester-wise RIs for maternal thyroid hormone status and use them for screening of pregnant women. How to cite this article Chakrabarty BK, Mitra B, Pal R, Hazra N. Specific Reference Intervals of Serum Triiodothyronine, Thyroxine, and Thyroid-stimulating Hormone in Normal Pregnant Indian Women as per Trimester. Indian J Med Biochem 2017;21(1):17-21.

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