Reference Intervals of Thyroid Function Tests in First Trimester Vietnamese Pregnant Women

2020 ◽  
Vol 66 (12/2020) ◽  
Author(s):  
Luong Ly ◽  
Nhu Vuong ◽  
Minh Chau ◽  
Hanh Phan ◽  
Quan Pham ◽  
...  
Author(s):  
Süleyman Akarsu ◽  
Filiz Akbiyik ◽  
Eda Karaismailoglu ◽  
Zeliha Gunnur Dikmen

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.


2021 ◽  
Vol 10 (11) ◽  
pp. 2444
Author(s):  
José María Hernández ◽  
Berta Soldevila ◽  
Inés Velasco ◽  
Fernando Moreno-Flores ◽  
Laura Ferrer ◽  
...  

Background: Recent guidelines recommend establishing a local reference interval (RI) for thyroid function. We aimed to establish trimester-specific RIs for thyrotropin (TSH) and free thyroxine (FT4) in a cohort of healthy pregnant women in Catalonia (Spain). Methods: A prospective observational study was conducted with 332 healthy pregnant women, from the first trimester (1T) to delivery. TSH was measured using an Architect® immunoassay (Abbott) and FT4 by two immunoassays, Architect® (Abbott) and Cobas® (Roche), in the three trimesters. FT4 was also measured by liquid chromatography mass spectrometry (LC/MS/MS) in the 1T. Results: TSH (µUI/mL) increased throughout pregnancy (1T: 0.03–3.78; 2T: 0.51–3.53; 3T: 0.50–4.32; p < 0.0001) and FT4 (pmol/L) progressively decreased (Architect® 1T: 10.42–15.96; 2T: 8.37–12.74; 3T: 8.24–12.49; p < 0.0001; and Cobas®: 1T: 11.46–19.05; 2T: 9.65–14.67; 3T: 8.88–14.54; p < 0.0067). The FT4 RI during 1T determined LC/MS/MS was 8.75–18.27. Despite the 1T FT4 results measured by LC/MS/MS and with the two immunoassays being significantly correlated, the results obtained by the three methods were found to be non-interchangeable. Conclusions: We established trimester-specific RIs for TSH and for FT4 with immunoassays in our population. We also validated the 1T FT4 using LC/MS/MS to confirm the results of FT4 lower than the 2.5th percentile or higher than the 97.5th percentile.


2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Ladan Mehran ◽  
Atieh Amouzegar ◽  
Hossein Delshad ◽  
Sahar Askari ◽  
Mehdi Hedayati ◽  
...  

Background. Due to many physiological changes during pregnancy, interpretation of thyroid function tests needs trimester-specific reference intervals for a specific population. There is no normative data documented for thyroid hormones on healthy pregnant women in Iran. The present survey was conducted to determine trimester-specific reference ranges for serum TSH, thyroxine (TT4), and triiodothyronine (TT3).Methods. The serum of 215 cases was analyzed for measurement of thyroid function tests by immunoassay method of which 152 iodine-sufficient pregnant women without thyroid autoantibodies and history of thyroid disorder or goiter were selected for final analysis. Reference intervals were defined as 5th and 95th percentiles.Results. Reference intervals in the first, second, and third trimesters were as follows: TSH (0.2–3.9, 0.5–4.1, and 0.6–4.1 mIU/l), TT4 (8.2–18.5, 10.1–20.6, and 9–19.4 μg/dl), and TT3 (137.8–278.3, 154.8–327.6, and 137–323.6 ng/dl), respectively. No correlation was found between TSH and TT4 or TT3. Significant correlation was found between TT4 and TT3 in all trimesters (r=0.35,P<0.001).Conclusion. The reference intervals of thyroid function tests in pregnant women differ among trimesters. Applying trimester-specific reference ranges of thyroid hormones is warranted in order to avoid misclassification of thyroid dysfunction during pregnancy.


2016 ◽  
Vol 20 (1) ◽  
pp. 101 ◽  
Author(s):  
Tarun Sekhri ◽  
JuhiAgarwal Juhi ◽  
Reena Wilfred ◽  
RatneshS Kanwar ◽  
Jyoti Sethi ◽  
...  

2012 ◽  
Vol 45 (13-14) ◽  
pp. 1114
Author(s):  
K. Mourabit Amari ◽  
L. Bondaz ◽  
J. Girouard ◽  
C. Gagnon ◽  
J. Weisnagel ◽  
...  

2018 ◽  
Vol 15 (2) ◽  
pp. 70
Author(s):  
NagwaRoshdy Mohamed ◽  
NerminAhmed Sheriba ◽  
NesmaAli Ibrahim ◽  
AhmedMagdy Hegab

2020 ◽  
Vol 11 ◽  
Author(s):  
Tal Schiller ◽  
Arnon Agmon ◽  
Viviana Ostrovsky ◽  
Gabi Shefer ◽  
Hilla Knobler ◽  
...  

IntroductionAn Israeli national survey found that 85% of pregnant women had urinary iodine content (UIC) levels below the adequacy range (&lt;150 µg/L). Widespread desalinated water usage and no national fortification plan are possible causes. Studies assessing relationships between iodine status and maternal and neonatal thyroid function provided varying results. Our aims were to determine whether iodine deficiency was associated with altered maternal or neonatal thyroid function and the factors leading to iodine deficiency.MethodsA cross-sectional study including 100 healthy women without prior thyroid disease, in their first trimester of a singleton pregnancy were recruited from an HMO clinic in central Israel. The women were followed from their first trimester. All women completed a 24-h dietary recall and life habits questionnaires. We tested for UIC, maternal and neonatal thyroid function, maternal autoantibodies, and neonatal outcomes.ResultsMedian UIC in our cohort was 49 µg/L [25%–75% interquartile range (IQR) 16-91.5 µg/L], with 84% below adequacy range. No correlation was found between iodine deficiency and maternal or neonatal thyroid function which remained within normal ranges. Antibody status did not differ, but thyroglobulin levels were significantly higher in iodine insufficient subjects. UIC was higher in women consuming an iodine containing supplement. There was no association between UIC and dietary iodine content or water source.ConclusionsModerate iodine deficiency is common in our healthy pregnant women population. Our data imply that moderate iodine deficiency in pregnancy seem sufficient to maintain normal maternal and neonatal thyroid function.


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