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

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.

scholarly journals Mild to moderate iodine deficiency in pregnancy: A matter of debate

2021 ◽  
Vol 5 (1) ◽  
pp. 018-026
Author(s):  
Delshad Hossein ◽  
Azizi Fereidoun
Keyword(s):  
Pregnant Women ◽  
Thyroid Function ◽  
Iodine Deficiency ◽  
Urinary Iodine ◽  
Iodine Concentration ◽  
Urinary Iodine Concentration ◽  
Iodine Nutrition ◽  
Iodine Supplementation ◽  
Iodine Deficiency In Pregnancy ◽  
In Pregnancy

During the last few decades painstaking efforts have been made to eliminate iodine deficiency through the world. Nowadays in regions where dietary iodine intake is adequate or borderline, the main focus is increasing dietary iodine supply in the target population during pregnancy and the first years of life. Severe iodine deficiency during pregnancy increases the risk of irreversible brain damage, intellectual disability, neurologic abnormalities, stunted growth, increased pregnancy loss, infant mortality, impairments in child development and cretinism. The potential effects of mild-to-moderate iodine deficiency are debated. Results from animal studies and observational human studies indicate that maternal mild-to-moderate iodine deficiency disturbs thyroid function in pregnancy and it also may affects fetal neurodevelopment. The effect of supplementation of iodine on thyroid function of pregnant women and their newborn, neurodevelopment of infants and cognitive performance of children have been investigated using iodine nutrition in pregnancy, based on median urinary iodine concentration. However they have found conflicting results regarding the benefits or harms of iodine supplementation in pregnancy. Although many epidemiological, interventional and clinical studies have supported the association between thyroid function in pregnant women and later psychomotor and mental development of their children, the effect of iodine supplementation in pregnant women on neurodevelopment of children is inconclusive. Even in areas with well-established universal salt iodization program, pregnancy could be at risk of having iodine deficiency and despite WHO/ICCIDD/UNICEF recommendation which believe that dietary iodine fortification during pregnancy depends primarily on the extent of pre-existing iodine deprivation, systematic dietary fortification needs to be implemented in this vulnerable group. However, iodine supplementation of mildly iodine deficient pregnant women may not have beneficial effects in their thyroid function or neurodevelopment of their children.

Assessment of iodine intake in mildly iodine-deficient pregnant women by a new automated kinetic urinary iodine determination method

2005 ◽  
Vol 43 (3) ◽  
Author(s):  
Mustafa Gültepe ◽  
Ömer Özcan ◽  
Osman Metin İpçioglu
Keyword(s):  
Pregnant Women ◽  
Iodine Deficiency ◽  
Urinary Iodine ◽  
Iodine Intake ◽  
Second Trimester ◽  
Third Trimester ◽  
Iodine Excretion ◽  
Iodine Deficiency In Pregnancy ◽  
Iodine Determination ◽  
In Pregnancy

AbstractMaternal iodine deficiency can compromise the thyroid status of the mother, fetus and newborn child. Therefore, it is important to assess the iodine excretion level of groups of pregnant women. In this study we aimed to determine iodine intake in pregnancy using a recently reported automated kinetic method for urinary iodine determination. Urinary iodine measurements of 123 pregnant women (18 first, 28 second and 77 third trimester) were carried out using a new automated kinetic assay based on the Sandell-Kolthoff reaction at 37°C and its kinetic measurement at 340nm in a random-access automated analyzer after ammonium persulfate digestion at 95°C in a water bath with ±0.1°C precision. Statistical analyses were carried out using SPSS software. Whole group, first trimester, second trimester and third trimester urinary iodine concentrations (mean±SD) in pregnant women were 1.13±0.81, 1.08±0.71, 0.86±0.58 and 1.27±0.87μmol/L, respectively. The urinary iodine concentration significantly increased with gestational age (p<0.05). We found that our study group was mildly iodine-deficient according to WHO criteria. Furthermore, the pregnant women were found to be mildly iodine-deficient in the first and third trimesters and moderately so in the second trimester. The only statistical difference was between second and third trimester values (p<0.05). Even though the increased iodine deficiency in the second trimester is not useful for early detection of iodine deficiency in pregnancy, the severity of this deficiency in the second trimester may lead to important effects on thyroid metabolism for both mother and fetus. Our study suggests that the iodine excretion of pregnant women living in iodine-deficient areas could be assessed using this fast and automated method.

scholarly journals Nutritional Iodine Status in Pregnant Women from Health Area IV in Asturias (Spain): Iodised Salt Is Enough

Nutrients ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 1816
Author(s):  
Silvia González-Martínez ◽  
María Riestra-Fernández ◽  
Eduardo Martínez-Morillo ◽  
Noelia Avello-Llano ◽  
Elías Delgado-Álvarez ◽  
...  
Keyword(s):  
Pregnant Women ◽  
Thyroid Function ◽  
Iodine Deficiency ◽  
Urinary Iodine ◽  
Multivariate Logistic Regression Analysis ◽  
First Trimester ◽  
Urinary Iodine Concentration ◽  
Iodine Status ◽  
Iodised Salt ◽  
Health Area

Background: Iodine deficiency during pregnancy may have adverse effects on the neurodevelopment of the foetus. Recent studies of pregnant women in Asturias (Spain) indicate that nutritional iodine levels are sufficient. The objective of this study was to confirm the appropriate nutritional iodine status and to analyse the influence of the ingestion of iodine on maternal urinary iodine concentration (UIC) and thyroid function. Methods: An observational study was carried out between May and June 2017 on women in the first trimester of pregnancy from Health Area IV in Asturias. The women completed a questionnaire related to their consumption of iodine and samples were taken to analyse UIC and thyroid function. Results: Three hundred and eighteen pregnant women were involved. Of these, 51.10% used iodised salt, 48.90% consumed ≥ 2 servings of dairy products daily and 87.08% took iodine supplements. The median UIC was 171.5 μg/L (116–265 μg/L) and 60.41% of women had UIC ≥ 150 μg/L. Multivariate logistic regression analysis demonstrated that iodised salt had a protective effect on UIC < 150 μg/L (odds ratio (OR) 0.404 (0.237–0.683), p = 0.001), but not iodine supplements (OR 0.512 (0.240–1.085), p = 0.080). The average level of thyroid stimulating hormone (TSH) was 2.26 ± 0.94 mIU/L; 68.40% of pregnant women taking iodine supplements had TSH < 2.5 mIU/L compared to 30.00% of those who were not taking supplements (p = 0.031). Conclusions: The pregnant women in our health area are maintaining appropriate nutritional iodine levels. The consumption of iodised salt protects against iodine deficiency; thus, iodine supplements should be taken on an individualised basis.

scholarly journals Management of thyroid disease in pregnancy – Room for improvement in the first trimester

2016 ◽  
Vol 9 (3) ◽  
pp. 126-129 ◽  
Author(s):  
Helen Robinson ◽  
Philip Robinson ◽  
Michael D’Emden ◽  
Kassam Mahomed
Keyword(s):  
General Practitioner ◽  
Thyroid Function ◽  
Thyroid Disease ◽  
Thyroid Dysfunction ◽  
First Trimester ◽  
Antenatal Clinic ◽  
Thyroid Stimulating Hormone ◽  
Thyroid Function Tests ◽  
In Pregnancy ◽  
Stimulating Hormone

Background First-trimester care of maternal thyroid dysfunction has previously been shown to be poor. This study evaluates early management of thyroid dysfunction in pregnancy in Australia. Methods Patients reviewed by the Obstetric Medicine team for thyroid dysfunction from 1 January 2012 to 30 June 2013 were included. Data were collected on gestation at referral from the patient’s general practitioner to the antenatal clinic, information provided in the referral letter, thyroid function tests and thyroid medications. Results Eighty-five women were included in the study. At the time of general practitioner referral to antenatal services, 19% of women with preexisting thyroid disease had no thyroid function tested. Forty-three percent had an abnormal thyroid-stimulating hormone defined as being outside the laboratory-specific pregnancy reference range if available, or outside the level of 0.1–2.5 mIu/L in the first trimester, 0.2–3.0 mIu/L in the second trimester and 0.3–3.0 mIu/L in the third trimester. Only 21% of women increased their thyroxine dose prior to their first antenatal clinic review. Conclusion This study highlights that a significant proportion of women with known thyroid disease either have untested thyroid function in the first trimester or a thyroid-stimulating hormone outside of levels recommended by guidelines.

scholarly journals Thyroid disorders in subfertility and early pregnancy

2020 ◽  
Vol 11 ◽  
pp. 204201882094585
Author(s):  
Samantha Anandappa ◽  
Mamta Joshi ◽  
Lukasz Polanski ◽  
Paul V. Carroll
Keyword(s):  
Pregnant Women ◽  
Thyroid Function ◽  
Current Knowledge ◽  
Thyroid Autoimmunity ◽  
Thyroid Disorders ◽  
Thyroid Function Tests ◽  
Increased Risk ◽  
Hormone Use ◽  
Current Knowledge Base ◽  
In Pregnancy

Disorders of thyroid function are common in pregnancy and have implications for foetal and maternal health. Thyroid autoimmunity, as evidenced by the presence of elevated levels of anti-thyroid antibodies (anti-TPO and anti-Tg antibodies) is associated with an increased risk of miscarriage, though the mechanism remains poorly understood. There has been considerable focus on the implications and optimal management of pregnant women with thyroid disease, especially those undergoing assisted reproduction. Pregnancy results in significant changes in thyroid physiology and these need to be understood by clinicians involved in the care of pregnant women. Guidelines for the use of thyroxine and target thyroid function tests have been produced by international bodies but it is recognised that these predominantly reflect expert opinion rather than established evidence-based practice. Importantly a number of key clinical trials have been performed to aid understanding, particularly of the consequences of hypothyroidism for mother and baby, and the effectiveness of thyroid hormone use in autoimmune and subclinical hypothyroidism. This review summarises the current knowledge base and guidance for practice relating to thyroid disorders in pregnancy and subfertility.

scholarly journals Association of Maternal Iodine Status With Child IQ: A Meta-Analysis of Individual Participant Data

2019 ◽  
Vol 104 (12) ◽  
pp. 5957-5967 ◽  
Author(s):  
Deborah Levie ◽  
Tim I M Korevaar ◽  
Sarah C Bath ◽  
Mario Murcia ◽  
Mariana Dineva ◽  
...  
Keyword(s):  
Iodine Deficiency ◽  
Meta Analysis ◽  
Urinary Iodine ◽  
First Trimester ◽  
Individual Participant Data ◽  
Verbal Iq ◽  
Iodine Status ◽  
Child Neurodevelopment ◽  
Individual Participant ◽  
In Pregnancy

Abstract Context Although the consequences of severe iodine deficiency are beyond doubt, the effects of mild to moderate iodine deficiency in pregnancy on child neurodevelopment are less well established. Objective To study the association between maternal iodine status during pregnancy and child IQ and identify vulnerable time windows of exposure to suboptimal iodine availability. Design Meta-analysis of individual participant data from three prospective population-based birth cohorts: Generation R (Netherlands), INMA (Spain), and ALSPAC (United Kingdom); pregnant women were enrolled between 2002 and 2006, 2003 and 2008, and 1990 and 1992, respectively. Setting General community. Participants 6180 mother-child pairs with measures of urinary iodine and creatinine concentrations in pregnancy and child IQ. Exclusion criteria were multiple pregnancies, fertility treatment, medication affecting the thyroid, and preexisting thyroid disease. Main Outcome Measure Child nonverbal and verbal IQ assessed at 1.5 to 8 years of age. Results There was a positive curvilinear association of urinary iodine/creatinine ratio (UI/Creat) with mean verbal IQ only. UI/Creat <150 µg/g was not associated with lower nonverbal IQ (−0.6 point; 95% CI: −1.7 to 0.4 points; P = 0.246) or lower verbal IQ (−0.6 point; 95% CI: −1.3 to 0.1 points; P = 0.082). Stratified analyses showed that the association of UI/Creat with verbal IQ was only present up to 14 weeks of gestation. Conclusions Fetal brain development is vulnerable to mild to moderate iodine deficiency, particularly in the first trimester. Our results show that potential randomized controlled trials investigating the effect of iodine supplementation in women with mild to moderate iodine deficiency on child neurodevelopment should begin supplementation not later than the first trimester.

scholarly journals Assessment of Thyroid Function in Early Pregnancy

2018 ◽  
Vol 19 (2) ◽  
pp. 98
Author(s):  
Mohammad Saifur Rahman ◽  
Sadia Sultana ◽  
Ayesha Nazneen
Keyword(s):  
Pregnant Women ◽  
Thyroid Function ◽  
Early Pregnancy ◽  
Correct Diagnosis ◽  
First Trimester ◽  
Military Hospital ◽  
Thyroid Disorders ◽  
Thyroid Disorder ◽  
Cross Sectional ◽  
In Pregnancy

<p><strong>Objectives:  </strong>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.</p><p><strong>Patients and Methods: </strong>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 FT<sub>3</sub>, FT<sub>4</sub>, 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 FT<sub>3</sub>, FT<sub>4</sub>, 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.</p><p><strong>Results:  </strong>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.</p><p><strong>Conclusion: </strong>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.</p><p>Bangladesh J. Nuclear Med. 19(2): 98-102, July 2016</p>

Gestation specific reference intervals for thyroid function tests in pregnancy

2016 ◽  
Vol 54 (8) ◽  
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.

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 ◽  
...  
Keyword(s):  
Pregnant Women ◽  
Thyroid Function ◽  
First Trimester ◽  
Reference Intervals ◽  
Thyroid Function Tests ◽  
Function Tests

scholarly journals Iodine Intake and Thyroid Function in Pregnant Women in a Private Clinical Practice in Northwestern Sydney before Mandatory Fortification of Bread with Iodised Salt

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Norman Blumenthal ◽  
Karen Byth ◽  
Creswell J. Eastman
Keyword(s):  
Pregnant Women ◽  
Thyroid Function ◽  
Iodine Deficiency ◽  
Urinary Iodine ◽  
Iodine Intake ◽  
Urinary Iodine Excretion ◽  
Blood Collection ◽  
Antenatal Visit ◽  
Urinary Iodine Concentration ◽  
Cross Sectional

Aim. The primary objective of the study was to assess the iodine nutritional status, and its effect on thyroid function, of pregnant women in a private obstetrical practice in Sydney.Methods. It was a cross-sectional study undertaken between November 2007 and March 2009. Blood samples were taken from 367 women at their first antenatal visit between 7 and 11 weeks gestation for measurement of thyroid stimulating hormone (TSH) and free thyroxine (FT4) levels and spot urine samples for urinary iodine excretion were taken at the same time as blood collection.Results. The median urinary iodine concentration (UIC) for all women was 81 μg/l (interquartile range 41–169 μg/l). 71.9% of the women exhibited a UIC of <150 μg/l. 26% of the women had a UIC <50 μg/l, and 12% had a UIC <20 μg/l. The only detectable influences on UIC were daily milk intake and pregnancy supplements. There was no statistically significant association between UIC and thyroid function and no evidence for an effect of iodine intake on thyroid function.Conclusions. There is a high prevalence of mild to moderate iodine deficiency in women in Western Sydney but no evidence for a significant adverse effect on thyroid function. The 6.5% prevalence of subclinical hypothyroidism is unlikely to be due to iodine deficiency.

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