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

2017 ◽  
Vol 21 (2) ◽  
pp. 96-100
Author(s):  
Nandita Hazra ◽  
Binay Mitra ◽  
Reetika Pal

ABSTRACT Aim Maternal thyroid hormone level during pregnancy is a vital parameter for the health of mother as well as developing child. Fetal growth is affected by maternal thyroid levels. Various physiological changes like alterations of thyroxine binding globulins (TBGs), beta-human chorionic gonadotropin (β-hCG) level, and change of iodide metabolism affect maternal thyroid hormone levels. Therefore, reference intervals (RI) for thyroid hormones in pregnant population require to be established separately from 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 using 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 (CIs) for the upper and lower reference limits were calculated. The values thus obtained were different from those provided by manufacturer kit literature. Conclusion It is recommended to determine own laboratory-specific, method-specific, trimester-wise RI for maternal thyroid hormone status and use them for screening of pregnant mothers. 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(2):96-100.

2017 ◽  
Vol 21 (1) ◽  
pp. 17-21
Author(s):  
Nandita Hazra ◽  
Binay Mitra ◽  
Reetika Pal

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.


2021 ◽  
Vol 53 (04) ◽  
pp. 272-279
Author(s):  
Chaochao Ma ◽  
Xiaoqi Li ◽  
Lixin Liu ◽  
Xinqi Cheng ◽  
Fang Xue ◽  
...  

AbstractThyroid hormone reference intervals are crucial for diagnosing and monitoring thyroid dysfunction during early pregnancy, and the dynamic change trend of thyroid hormones during pregnancy can assist clinicians to assess the thyroid function of pregnant women. This study aims to establish early pregnancy related thyroid hormones models and reference intervals for pregnant women. We established two derived databases: derived database* and derived database#. Reference individuals in database* were used to establish gestational age-specific reference intervals for thyroid hormones and early pregnancy related thyroid hormones models for pregnant women. Individuals in database# were apparently healthy non-pregnant women. The thyroid hormones levels of individuals in database# were compared with that of individuals in database* using nonparametric methods and the comparative confidence interval method. The differences in thyroid stimulating hormone and free thyroxine between early pregnant and non-pregnant women were statistically significant (p<0.0001). The reference intervals of thyroid stimulating hormone, free thyroxine and free triiodothyronine for early pregnant women were 0.052–3.393 μIU/ml, 1.01–1.54 ng/dl, and 2.51–3.66 pg/ml, respectively. Results concerning thyroid stimulating hormone and free thyroxine reference intervals of early pregnancy are comparable with those from other studies using the same detection platform. Early pregnancy related thyroid hormones models showed various change patterns with gestational age for thyroid hormones. Early pregnancy related thyroid hormones models and reference intervals for pregnant women were established, so as to provide accurate and reliable reference basis for the diagnosing and monitoring of maternal thyroid disfunction in early pregnancy.


2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Yonghong Sheng ◽  
Dongping Huang ◽  
Shun Liu ◽  
Xuefeng Guo ◽  
Jiehua Chen ◽  
...  

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.


Author(s):  
Frank A. Quinn ◽  
Gennady N. Gridasov ◽  
Sergey A. Vdovenko ◽  
Natalia A. Krasnova ◽  
Nadezhda V. Vodopianova ◽  
...  

AbstractUndiagnosed thyroid disease is a common problem with significant public health implications. This is especially true during pregnancy, when the health of both the mother and the developing child can be adversely affected by abnormal maternal thyroid function. Measurement of serum thyroid stimulating hormone (TSH) and thyroid peroxidase antibodies (TPO-Ab) are two common ways to assess maternal thyroid status. The objective of our study was to determine the prevalence of abnormal TSH and TPO-Ab tests in a population of pregnant women in the Samara region of the Russian Federation. Serum samples were obtained from 1588 pregnant women as part of their routine antenatal care. TSH and TPO-Ab were measured, and trimester-specific reference values for TSH (2.5–97.5 percentiles) were calculated using TPO-Ab-negative women. TSH results outside these ranges were considered abnormal; TPO-Ab levels outside the manufacturer's reference range (>12IU/mL) were considered abnormal. Overall, the prevalence of abnormal results was 6.3% for TSH and 10.7% for TPO-Ab. High TSH (>97.5 trimester-specific percentile) and TPO-Ab-positive results were most common in the first trimester (5.7% and 13.8%, respectively). TSH levels were associated with gestational age and TPO-Ab status, and with maternal age in TPO-Ab-negative women. TPO-Ab status was associated with both maternal and gestational age. Women with TSH >2.5mIU/L had a significantly increased risk of being TPO-Ab-positive, and this risk increased with age. Based on our data, we conclude that abnormal TSH and TPO-Ab are common in pregnant women of the Samara region. Given the association of thyroid dysfunction to adverse pregnancy outcomes, screening of this population for abnormal thyroid function should be considered.


Author(s):  
Ying Guo ◽  
Bin Wei ◽  
Wei Dai ◽  
Hongjian Xie

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.


Author(s):  
Julian H Barth ◽  
Ahai Luvai ◽  
Nuthar Jassam ◽  
Wycliffe Mbagaya ◽  
Eric S Kilpatrick ◽  
...  

Introduction Reference intervals are dependent on the reference population, the analytical methods and the way the data are handled statistically. Individual method-related differences have been studied but the comparative differences in reference intervals have not. Methods We studied a reference population of healthy adult subjects and measured free thyroxine and thyroid-stimulating hormone by the four most commonly used analytical platforms used in the UK. Subjects were excluded if they were > 65 years or had positive thyroid peroxidase antibodies. We also performed a systematic literature review of thyroid hormone reference interval studies in non-pregnant adults. Results In total, 303 subjects were recruited and 42 excluded. The central 95th centile values for thyroid-stimulating hormone (mIU/L) were Abbott Architect (0.51–3.67); Beckman Unicel DxI (0.57–3.60); Roche Cobas (0.60–4.31) and Siemens Advia Centaur XP (0.63–4.29). The 95th centile values for thyroxine (pmol/L) were Abbott Architect (10.6–15.5); Beckman Unicel DxI (7.9–13.0); Roche Cobas (12.5–19.6) and Siemens Advia Centaur XP (11.8–19.0). We identified 55 papers describing thyroid reference intervals in male and non-pregnant female adults. The values for upper and lower reference intervals by manufacturer varied but were not significantly different for thyroid-stimulating hormone but were for thyroxine. Discussion Our study demonstrates clearly that there are marked variations in the reference intervals for thyroid hormones between analytical platforms. There is an urgent need for standardization of thyroid hormone assays to permit transferability of results. Until then, guidelines will need to reflect this method-related difference.


2019 ◽  
Vol 51 (4) ◽  
pp. 416-422
Author(s):  
Guocheng Wang ◽  
Guojun Zhang

Abstract Objective To describe the diverse upper reference limits of serum thyroid stimulating hormone on the same platform for pregnant women in China. Methods The trimester-specific and population-specific TSH reference intervals for pregnant women were established, and then 5 reference intervals on the same platform in China were compared with the reference intervals derived from the present study and the manufacturer. Results The most striking difference in the upper reference limits of TSH among 5 reference intervals on the same platform was shown at the first trimester of pregnancy. The calculated regional prevalence rates of subclinical thyroid diseases varied using the data derived from 30,771 pregnant women who visited the largest obstetric center in our district from 2008 to 2018. Conclusion We reported differences among 7 reference intervals of TSH on the same platform and showed the changing population factors significantly affected them.


2007 ◽  
Vol 157 (4) ◽  
pp. 509-514 ◽  
Author(s):  
Rt Stricker ◽  
M Echenard ◽  
R Eberhart ◽  
M-C Chevailler ◽  
V Perez ◽  
...  

Background: Maternal thyroid dysfunction has been associated with a variety of adverse pregnancy outcomes. Laboratory measurement of thyroid function plays an important role in the assessment of maternal thyroid health. However, occult thyroid disease and physiologic changes associated with pregnancy can complicate interpretation of maternal thyroid function tests (TFTs). Objective and methods: To 1) establish the prevalence of laboratory evidence for autoimmune thyroid disease (AITD) in pregnant women; 2) establish gestational age-specific reference intervals for TFTs in women without AITD; and 3) examine the influence of reference intervals on the interpretation of TFT in pregnant women. Serum samples were collected from 2272 pregnant women, and TFT performed. Gestational age-specific reference intervals were determined in women without AITD, and then compared with the non-pregnant assay-specific reference intervals for interpretation of testing results. Results: Thyroid peroxidase antibodies (TPO-Ab) and thyroglobulin antibodies (Tg-Ab) were positive in 10.4 and 15.7% of women respectively. TPO-Ab level was related to maternal age, but TPO-Ab status, Tg-Ab status, and Tg-Ab level were not. Women with TSH > 3.0 mIU/l were significantly more likely to be TPO-Ab positive. Gestational age-specific reference intervals for TFT were significantly different from non-pregnant normal reference intervals. Interpretation of TFT in pregnant women using non-pregnant reference intervals could potentially result in misclassification of a significant percentage of results (range: 5.6–18.3%). Conclusion: Laboratory evidence for thyroid dysfunction was common in this population of pregnant women. Accurate classification of TFT in pregnant women requires the use of gestational age-specific reference intervals.


2020 ◽  
Author(s):  
Cheng Huang ◽  
Ying Wu ◽  
Linong Chen ◽  
Zhiya Yuan ◽  
Shuzhe Yang ◽  
...  

Abstract Background: The reference intervals of thyroid hormone will change at different stages of pregnancy because of physiological alterations. On the other hand, the reference intervals of hyroid hormone will also change in different detection systems due to manufacturer’s methodology as well as different race. The objective in this study was to establish the assay method- and trimester-specific reference intervals for thyroid stimulating hormone, free thyroxine, and free triiodothyronine for pregnant women in the Chengdu.Methods: A prospective, population-based cohort study involved 23701 reference samples of pregnant women during the three trimesters and 8646 non-pregnant women with pre-pregnancy clinical and laboratory tests. The 2.5th and 97.5th percentiles were calculated as the reference intervals for thyroid stimulating hormone, free thyroxine, and free triiodothyronine at each trimester of pregnant women according to ATA Guidelines.Results: The reference interval of thyroid stimulating hormone in the 2.5th and 97.5th percentiles has a significant increasing trend from first trimester, to second trimester, and to third trimester, which was 0.08-3.79 mIU/L for first trimester, and 0.12-3.95 mIU/L for second trimester, and 0.38-4.18 mIU/L for third trimester, respectively (P < 0.001). However, the reference intervals of free thyroxine and free triiodothyronine in the 2.5th and 97.5th percentiles have significant decreasing trends from first trimester, to second trimester, and to third trimester, which were 11.87-18.83 pmol/L and 3.77-5.50 pmol/L for first trimester, and 11.22-18.19 pmol/L and 3.60-5.41 pmol/L for second trimester, and 10.19-17.42 pmol/L and 3.37-4.79 pmol/L for third trimester, respectively (both P < 0.001).Conclusion: It is necessary to establish assay method- and trimester-specific reference intervals for thyroid stimulating hormone, free thyroxine, and free triiodothyronine because the reference intervals of these thyroid hormones are significantly different at different stages of pregnancy.


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