Reference values and universal screening of thyroid function in the first trimester of the population of pregnant women in Toledo (Spain)

Objectives: Thyroid disorders are commonly observed in pregnancy. Thyroid hormones play an important role in embryogenesis and fetal development. The fetus is completely dependent on the mother for thyroid hormone in first trimester. About 10% of all pregnant women can be affected by thyroid disorders during pregnancy. Thyroid function abnormalities in pregnancy are a challenge for the concerned physicians. The objective of this study was to assess the maternal thyroid function in first trimester of pregnancy.Patients and Methods: A descriptive cross sectional study was carried out at the Combined Military Hospital (CMH), Dhaka over a period of one year from January 2013 to December 2013 to see the serum FT3, FT4, TSH, thyroid antibodies level and common thyroid disorders in pregnancy. A total of 138 pregnant women in their first trimester (up to 12 weeks) of pregnancy with an age range of 18-35 years were enrolled in this study. Pregnant women with known thyroid disorder and on treatment and pregnancy more than three months were excluded. Measurement of serum FT3, FT4, TSH, Anti TPO-Ab and Anti TG-Ab were done in each patient at the time of enrolment. Ultrasonography of each patient was done for confirmation of pregnancy and correlation of gestational age.Results: Among 138 pregnant women, subclinical hypothyroidism was detected in 10 (7.2%) patients and subclinical hyperthyroidism was detected in 3 (2.2%) patients. Mean difference of the investigation findings were not statistically significant among primi and multi gravida. TPO-Ab and TG-Ab difference were statistically significant between two age groups.Conclusion: Subclinical thyroid disorders are fairly high among pregnant women. Correct diagnosis in early pregnancy and prompt treatment will bring an excellent prognosis for both mother and offspring.Bangladesh J. Nuclear Med. 19(2): 98-102, July 2016

Download Full-text

Distribution of thyroid peroxidase positivity and its effects on thyroid function in normal pregnant women during 1st trimester in Dhaka city

Update Dental College Journal ◽

10.3329/updcj.v4i1.21160 ◽

2014 ◽

Vol 4 (1) ◽

pp. 15-20

Author(s):

Ohida Sultanaa ◽

Nasim Jahan ◽

Nayma Sultana ◽

Farzana Mahmudad ◽

Tazdik G Chowdhurye

Keyword(s):

Pregnant Women ◽

Thyroid Function ◽

First Trimester ◽

Normal Pregnancy ◽

Control Group ◽

Thyroid Peroxidase ◽

Study Group ◽

Cross Sectional ◽

Total Study Population ◽

Group B

Objective: To measure the distribution of TPO-Ab positivity and to observe the effect of thyroid peroxidase positivity on thyroid function during first trimester in normal pregnancy. Method: A cross sectional among 120 subjects were taken in this study and divided into control and study groups. Control group (Group A) consisted of 60 healthy non pregnant women age ranged between 20 to 35 years. Study group (Group B) consisted of 60 normal pregnant women of same age range. Group B was further subdivided into group B1 and group B2according to the level of TPO-Ab. Group B1 consisted of TPO-Ab positive pregnant women and group B2 consisted of TPO- Ab negative pregnant women. Control group was selected from personal contacts and study group from Out Patient Department (OPD) of Obstetrics and Gynecology of Sir Salimullah Medical College and Mitford Hospital. For assessment of thyroid function, serum free thyroxine (FT4), thyroid stimulating hormone (TSH) were measured. Serum FT4, TSH were measured by Enzyme link immunosorbant (ELISA) method. Again, serum TPO-Ab of total study population and hCG of all the pregnant women were measured. Serum TPO-Ab by Micro particle Enzyme Immunoassay (MEIA) method and hCG was estimated by ELISA. Statistical analysis was done by SPSS version 17. Results: In this study, serum FT4 and was significantly (P<0.001) higher and TSH level was significantly (P<0.001) lower in normal pregnant women during 1st trimester in comparison to those of non pregnant women. Again, 18% of pregnant women showed TPO-Ab positivity. However, serum FT4 level was significantly (P<0.001) lower whereas, TSH level was significantly (p<0.001) higher in TPO-Ab positive pregnant women in comparison to those of TPO-Ab negative pregnant women. Conclusion: TPO-Ab positivity increases during 1st trimester of normal pregnancy which decreases the hyper functional state of thyroid hormones. So, thyroid screening should be done routinely during pregnancy. DOI: http://dx.doi.org/10.3329/updcj.v4i1.21160 Update Dent. Coll. j: 2014; 4 (1): 15-20

Download Full-text

Moderate Iodine Deficiency Is Common in Pregnancy but Does Not Alter Maternal and Neonatal Thyroid Function Tests

Frontiers in Endocrinology ◽

10.3389/fendo.2020.523319 ◽

2020 ◽

Vol 11 ◽

Author(s):

Tal Schiller ◽

Arnon Agmon ◽

Viviana Ostrovsky ◽

Gabi Shefer ◽

Hilla Knobler ◽

...

Keyword(s):

Pregnant Women ◽

Thyroid Function ◽

Iodine Deficiency ◽

Urinary Iodine ◽

Iodine Content ◽

First Trimester ◽

Thyroid Function Tests ◽

Neonatal Thyroid Function ◽

Iodine Deficiency In Pregnancy ◽

In Pregnancy

IntroductionAn Israeli national survey found that 85% of pregnant women had urinary iodine content (UIC) levels below the adequacy range (<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.

Download Full-text

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.

Download Full-text

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

Clinical Laboratory ◽

10.7754/clin.lab.2020.200415 ◽

2020 ◽

Vol 66 (12/2020) ◽

Author(s):

Luong Ly ◽

Nhu Vuong ◽

Minh Chau ◽

Hanh Phan ◽

Quan Pham ◽

...

Keyword(s):

Pregnant Women ◽

Thyroid Function ◽

First Trimester ◽

Reference Intervals ◽

Thyroid Function Tests ◽

Function Tests

Download Full-text

Reference values and universal screening of thyroid dysfunction in pregnant women

Endocrinología y Nutrición (English Edition) ◽

10.1016/j.endoen.2014.06.006 ◽

2014 ◽

Vol 61 (6) ◽

pp. 336-338

Author(s):

Gonzalo Díaz-Soto ◽

Encarna Largo ◽

Cristina Álvarez-Colomo ◽

Isabel Martínez-Pino ◽

Daniel de Luis

Keyword(s):

Pregnant Women ◽

Reference Values ◽

Universal Screening ◽

Thyroid Dysfunction

Download Full-text

Perchlorate and Thiocyanate Exposure and Thyroid Function in First-Trimester Pregnant Women

The Journal of Clinical Endocrinology & Metabolism ◽

10.1210/jc.2010-0014 ◽

2010 ◽

Vol 95 (7) ◽

pp. 3207-3215 ◽

Cited By ~ 81

Author(s):

Elizabeth N. Pearce ◽

John H. Lazarus ◽

Peter P. A. Smyth ◽

Xuemei He ◽

Daniela Dall'Amico ◽

...

Keyword(s):

Pregnant Women ◽

Thyroid Function ◽

Sodium Iodide ◽

Urinary Iodine ◽

First Trimester ◽

Iodine Intake ◽

Sodium Iodide Symporter ◽

Free T4 ◽

Cross Sectional ◽

Serum Tsh

Context: Thyroid hormone, requiring adequate maternal iodine intake, is critical for fetal neurodevelopment. Perchlorate decreases thyroidal iodine uptake by competitively inhibiting the sodium/iodide symporter. It is unclear whether environmental perchlorate exposure adversely affects thyroid function in pregnant women. Thiocyanate, derived from foods and cigarette smoke, is a less potent competitive sodium/iodide symporter inhibitor than perchlorate. Objective: Our objective was to determine whether environmental perchlorate and/or thiocyanate exposure is associated with alterations in thyroid function in pregnancy. Design and Setting: We conducted a cross-sectional study at health centers in Cardiff, Wales, and Turin, Italy. Patients: During 2002–2006, 22,000 women at less than 16 wk gestation were enrolled in the Controlled Antenatal Thyroid Screening Study. Subsets of 261 hypothyroid/hypothyroxinemic and 526 euthyroid women from Turin and 374 hypothyroid/hypothyroxinemic and 480 euthyroid women from Cardiff were selected based on availability of stored urine samples and thyroid function data. Main Outcome Measures: Urinary iodine, thiocyanate, and perchlorate and serum TSH, free T4 (FT4), and thyroperoxidase antibody were measured. Results: Urinary iodine was low: median 98 μg/liter in Cardiff and 52 μg/liter in Turin. Urine perchlorate was detectable in all women. The median (range) urinary perchlorate concentration was 5 μg/liter (0.04–168 μg/liter) in Turin and 2 μg/liter (0.02–368 μg/liter) in Cardiff. There were no associations between urine perchlorate concentrations and serum TSH or FT4 in the individual euthyroid or hypothyroid/hypothyroxinemic cohorts. In multivariable linear analyses, log perchlorate was not a predictor of serum FT4 or TSH. Conclusions: Low-level perchlorate exposure is ubiquitous but did not affect thyroid function in this cohort of iodine-deficient pregnant women.

Download Full-text

Thyroid Function Reference Values in Healthy Iodine-Sufficient Pregnant Women and Influence of Thyroid Nodules on Thyrotropin and Free Thyroxine Values

Thyroid ◽

10.1089/thy.2018.0324 ◽

2019 ◽

Vol 29 (3) ◽

pp. 421-429 ◽

Cited By ~ 4

Author(s):

M. Dolores Ollero ◽

Marta Toni ◽

José Javier Pineda ◽

Juan Pablo Martínez ◽

Mercedes Espada ◽

...

Keyword(s):

Pregnant Women ◽

Thyroid Function ◽

Reference Values ◽

Thyroid Nodules ◽

Free Thyroxine

Download Full-text

First trimester thyroid function in pregnant women residing in Saint Petersburg (Russia): reference values and risk of gestational diabetes

Diabetes Mellitus ◽

10.14341/dm9283 ◽

2018 ◽

Vol 21 (1) ◽

pp. 34-41

Author(s):

Polina V. Popova ◽

Ekaterina S. Shilova ◽

Alexandra S. Tkachuk ◽

Alexandra V. Dronova ◽

Anna D. Anopova ◽

...

Keyword(s):

Gestational Diabetes ◽

Pregnant Women ◽

Reference Values ◽

Subclinical Hypothyroidism ◽

Reference Interval ◽

First Trimester ◽

Specific Reference ◽

Thyroid Status ◽

Saint Petersburg ◽

Increased Risk

Background. Subclinical hypothyroidism during pregnancy and gestational diabetes mellitus (GDM) is known to be associated with maternal and child morbidity. The concept of subclinical dysfunction of the thyroid gland in pregnant women depends on the population-specific and trimester-specific reference values so fixed universal cutoff concentrations for thyroid-stimulating hormone (TSH) that were recommended earlier now are put under the question. Population-specific and trimester-specific reference values have not been defined for pregnant women residing in Saint Petersburg. The data concerning the association of maternal thyroid status with GDM development are controversial. Aims. The aim of the study was to determine the reference values of TSH and free thyroxin (fT4) in the first trimester of pregnancy in women living in St. Petersburg, and to assess the relationship between thyroid status and the risk of subsequent development of GDM. Materials and methods. The levels of TSH, fT4 and thyroid peroxidase antibodies (TPO-Ab) were analyzed in 503 pregnant women before the 14th week of gestation. The women underwent oral glucose tolerance test (OGTT) at 2428 weeks to find out those with GDM. The association between thyroid function, thyroid autoimmunity and the risk of GDM we estimated. Results. The reference values for TSH were 0.07 4.40 mU /L, and for fT4 11.7 20.3 pmol/L. The prevalence of subclinical hypothyroidism in the 503 pregnant women was 16.9% according to the diagnostic criteria of TSH 2.5 mIU / L and 3.8% using our calculated reference interval. Hypothyroxinemia was registered in 5,3% using reference values recommended by diagnostic tests manufacturer and in 2,8% according to our calculated reference interval for fT4. GDM was diagnosed in 23% of women. Logistic regression analysis showed associations of hypothyroxinemia and TPO-Ab-positivity with the increased risk of GDM that remained significant after adjustments on age and body mass index (BMI) [adjusted OR (95% CI) = 7.39 (1.2742.93) for hypothyroxinemia, p=0.026; and adjusted OR (95% CI) = 2.02 (1.014.04) for TPO-Ab-positivity, p=0.047). Conclusions. Reference intervals for first trimester TSH and fT4 have been established for pregnant women living in St. Petersburg. Hypothyroxinemia and TPO-Ab-positivity were associated with the increased risk of GDM.

Download Full-text

Mild Anemia May Affect Thyroid Function in Pregnant Chinese Women During the First Trimester

Frontiers in Endocrinology ◽

10.3389/fendo.2021.772917 ◽

2021 ◽

Vol 12 ◽

Author(s):

Guan-ying Nie ◽

Rui Wang ◽

Peng Liu ◽

Ming Li ◽

Dian-jun Sun

Keyword(s):

Pregnant Women ◽

Thyroid Function ◽

Normal Control ◽

Subclinical Hypothyroidism ◽

First Trimester ◽

Specific Reference ◽

American Thyroid Association ◽

Mild Anemia ◽

Upper Limit ◽

Tsh Levels

BackgroundPregnant women are often susceptible to anemia, which can damage the thyroid gland. However, compared with moderate and severe anemia, less attention has been paid to mild anemia. The purpose of this study was to evaluate the effect of mild anemia on the thyroid function in pregnant women during the first trimester.MethodsA total of 1,761 women in the first trimester of their pregnancy were enrolled from Shenyang, China, and divided into mild anemia and normal control groups based on their hemoglobin levels. Thyroid-stimulating hormone (TSH), free thyroxine (FT4), and free triiodothyronine (FT3) levels were compared between the two groups.ResultsThe TSH levels of pregnant women with mild anemia were higher than those of pregnant women without mild anemia (p < 0.05). Normal control women were selected to set new reference intervals for TSH, FT3, and FT4 levels during the first trimester, which were 0.11–4.13 mIU/l, 3.45–5.47 pmol/l, and 7.96–16.54 pmol/l, respectively. The upper limit of TSH 4.13 mU/l is close to the upper limit 4.0 mU/l recommended in the 2017 American Thyroid Association (ATA) guidelines, indicating that exclusion of mild anemia may reduce the difference in reference values from different regions. Mild anemia was related to 4.40 times odds of abnormally TSH levels (95% CI: 2.84, 6.76) and 5.87 increased odds of abnormal FT3 (95% CI: 3.89, 8.85). The proportion of hypothyroidism and subclinical hypothyroidism in patients with mild anemia was higher than that in those without anemia (0.6% vs. 0, p = 0.009; 12.1% vs. 1.9%, p < 0.001). Mild anemia was related to 7.61 times increased odds of subclinical hypothyroidism (95% CI: 4.53, 12.90).ConclusionsMild anemia may affect thyroid function during the first trimester, which highlights the importance of excluding mild anemia confounding when establishing a locally derived specific reference interval for early pregnancy.

Download Full-text