Department of Internal Medicine, Chung-Ang University Hospital, Seoul, Korea
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Cancer Research Institute, Seoul National University College of Medicine, Seoul, Korea
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Cancer Research Institute, Seoul National University College of Medicine, Seoul, Korea
Integrated Major in Innovative Medical Science, Seoul National University College of Medicine, Seoul, Korea
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Department of Molecular Medicine and Biopharmaceutical Sciences, Graduate School of Convergence Science and Technology, Seoul National University, Seoul, Korea
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Department of Molecular Medicine and Biopharmaceutical Sciences, Graduate School of Convergence Science and Technology, Seoul National University, Seoul, Korea
Department of Nuclear Medicine, Seoul National University College of Medicine, Seoul, Korea
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Objective
This study aimed to assess selenium status in South Korean pregnant women and its impact on maternal thyroid function and pregnancy outcomes.
Methods
‘Ideal Breast Milk (IBM) Cohort Study’ included 367 pregnant women out of 442 participants and categorized into three groups based on plasma selenium levels: deficient (< 70 μg/L), suboptimal (70–99 μg/L), and optimal (≥ 100 μg/L). During the second or third trimester, various blood parameters, including selenium, thyroid-stimulating hormone, free T4, free T3, and anti-thyroid peroxidase antibody levels, were measured. Thyroid parenchymal echogenicity was assessed as another surrogate marker for thyroid autoimmunity using ultrasonography.
Results
The median plasma selenium was 98.8 (range: 46.7–206.4) μg/L, and 30 individuals (8%) were categorized as deficient, while 164 (45%) were classified in the suboptimal group. Selenium deficiency was associated with markers of autoimmune thyroiditis, including positive anti-thyroid peroxidase antibody results (13.3 (deficient) vs 4.6 (optimal) %, P = 0.031) and thyroid parenchymal heterogeneity on ultrasound (33.3 (deficient) vs 14.6 (suboptimal) vs 17.3 (optimal) %, P = 0.042), independently of gestational age. The incidence of severe preeclampsia was higher in the group not taking selenium supplements, particularly among those with twin pregnancies, compared to the group taking selenium supplements (0 (selenium supplement) vs 9.0 (no supplement) %, P = 0.015).
Conclusion
Pregnant women experience mild selenium deficiency, which can lead to significant health issues including maternal thyroid autoimmunity and obstetrical complications during pregnancy. Guidelines for appropriate selenium intake according to the stage of pregnancy and the number of fetuses are needed.
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Background
Current guidelines recommend different postpartum approaches for patients started on levothyroxine (LT4) during pregnancy.
Objective
We studied the postpartum management of these patients and determined factors associated with long-term hypothyroidism.
Methods
A retrospective study was conducted at a tertiary center between 2014 and 2020, with LT4 initiation according to 2014 ETA recommendations. We performed multivariate logistic regression (MVR) and a receiver operating characteristic curve analysis to determine variables associated with long-term hypothyroidism and their optimal cutoffs.
Results
LT4 was initiated in 177 pregnant women, and 106/177 (60%) were followed at long-term (at least 6 months post partum) (28.5 (9.0–81.9) months). LT4 could have been stopped in 45% of patients who continued it immediately after delivery. Thirty-six out of 106 (34%) patients were long-term hypothyroid. In them, LT4 was initiated earlier during pregnancy than in euthyroid women (11.7 ± 4.7 vs 13.7 ± 6.5 weeks, P = 0.077), at a higher thyroid-stimulating hormone (TSH) level (4.1 (2.2–10.1) vs 3.5 (0.9–6.9) mU/L, P = 0.005), and reached a higher dose during pregnancy (62.8 ± 22.2 vs 50.7 ± 13.9 µg/day, P = 0.005). In the MVR, only the maximal LT4 dose during pregnancy was associated with long-term hypothyroidism (odds ratio (OR) = 1.03, 95% CI: 1.00–1.05, P = 0.003). The optimal cutoffs for predicting long-term hypothyroidism were an LT4 dose of 68.75 µg/day (87% specificity, 42% sensitivity; P = 0.013) and a TSH level ≥ 3.8 mU/L (68.5% specificity, 77% sensitivity; P = 0.019).
Conclusion
One-third of the patients who started on LT4 during pregnancy had long-term hypothyroidism. The TSH level at treatment initiation and the LT4 dose during pregnancy could guide the decision for continuing long-term LT4.
Department of Clinical Research, Faculty of Health Sciences, University of Southern Denmark, Odense, Denmark
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Department of Clinical Research, Faculty of Health Sciences, University of Southern Denmark, Odense, Denmark
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Department of Clinical Research, Faculty of Health Sciences, University of Southern Denmark, Odense, Denmark
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Department of Clinical Research, Faculty of Health Sciences, University of Southern Denmark, Odense, Denmark
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Objective
Maternal thyroid autoimmunity and thyroid function in early pregnancy may impact fetal neurodevelopment. We aimed to investigate how thyroid autoimmunity and thyroid function in early pregnancy were associated with language acquisition in offspring at 12–36 months of age.
Methods
This study was embedded in the prospective Odense child cohort. Mother–child dyads were excluded in case of maternal intake of thyroid medication during pregnancy. The parents completed MacArthur–Bates Communicative Development Inventories (MB-CDI) every third month to assess their offspring’s productive vocabulary. All completed reports for each child were included in the analyses. Logistic growth curve models evaluated associations between MB-CDI scores and levels of maternal thyroid peroxidase antibodies (TPOAb), free thyroxine (FT4), and thyrotropin, respectively, measured in early pregnancy (median gestational week 12). All models were stratified by offspring sex and adjusted for maternal age, education, pre-pregnancy body mass index, parity, breastfeeding, and offspring age.
Results
The study included 735 mother–child dyads. Children born to mothers with TPOAb ≥11 kIU/L, opposed to TPOAb <11 kIU/L, had a lower probability of producing words at age 18–36 months for girls (OR = 0.78, P < 0.001) and 33–36 months for boys (OR = 0.83, P < 0.001). The probability of producing words was higher in girls at 30–36 months of age with low-normal maternal FT4 vs high-normal FT4 (OR = 0.60, P < 0.001), and a similar trend was seen in boys. Results were ambiguous for thyrotropin.
Conclusion
In women without known thyroid disease, TPOAb positivity in early pregnancy was negatively associated with productive vocabulary acquisition in girls and boys. This association was not mediated by a decreased thyroid function, as low-normal maternal FT4, unexpectedly, indicated better vocabulary acquisition. Our results support that maternal thyroid autoimmunity per se may affect fetal neurodevelopment.
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Objective
Pregnancy is a state of physiological inflammation facilitating implantation. Early isolated hypothyroxinaemia (IH) and increased inflammation (including obesity) have been associated with severe obstetric complications. The current study evaluated the association between IH, low ferritin and inflammation parameters (interleukin 6 (IL-6), C-reactive protein (CRP), human chorionic gonadotrophin (hCG) and obesity. Moreover, the course of these parameters throughout pregnancy was evaluated in relation to IH.
Methods
In the cross-sectional study (A) at 12 weeks, 2759 women participated and 2433 participated in the longitudinal study (B) with assessments at 12, 20 and 28 weeks gestation. At the first trimester, 122 (4.4%) IH women (free thyroxine (FT4) <5th percentile, normal TSH levels) were compared with 2114 (76.6%) reference women (FT4 between tenth and 90th percentiles, normal thyrotrophin (TSH) levels), in study B these figures were 99 (4.1%) and 1847 (75.9%), respectively.
Results
Cross-sectionally, compared to reference women, IH was independently associated with low ferritin (<5th percentile, OR: 2.6, 95% CI: 1.4–4.9), high CRP (>95th percentile: OR: 1.9, 95% CI: 1.04–3.7), low hCG (<median, OR: 2.1, 95% CI: 1.40–3.16), obesity (BMI > 30, OR: 1.7, 95% CI: 1.12.9) and higher age (OR: 1.1, 95% CI: 1.04–1.15). Longitudinally, compared to reference women, women with IH at 12 weeks gestation showed persistently and significantly lower ferritin and hCG levels, and persistently higher CRP and IL-6 levels throughout gestation.
Conclusion
Gestational IH could be viewed as a condition of increased inflammation, as reported in non-thyroidal illness syndrome. Less favourable inflammation parameters and low iron status during early gestation in IH women seem to persist throughout gestation.
Istituti Clinici Scientifici Maugeri IRCCS, Unit of Endocrinology and Metabolism, Laboratory for Endocrine Disruptors, Pavia (PV), Italy
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Istituti Clinici Scientifici Maugeri IRCCS, Unit of Endocrinology and Metabolism, Laboratory for Endocrine Disruptors, Pavia (PV), Italy
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Istituti Clinici Scientifici Maugeri IRCCS, Unit of Endocrinology and Metabolism, Laboratory for Endocrine Disruptors, Pavia (PV), Italy
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Istituti Clinici Scientifici Maugeri IRCCS, Unit of Endocrinology and Metabolism, Laboratory for Endocrine Disruptors, Pavia (PV), Italy
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Objective
Obesity is associated with increased thyroid-stimulating hormone (TSH) in non-pregnant subjects, but this phenomenon has not been fully characterized during pregnancy. Our aim was to evaluate the impact of BMI on first-trimester TSH in a wide cohort of pregnant women with negative anti-thyroperoxidase antibodies (AbTPO) and its implications on uterine artery pulsatility index (UtA-PI), a marker of early placentation.
Methods
The study included 2268 AbTPO-negative pregnant women at their first antenatal visit. Anamnestic data, BMI, TSH, anti-nuclear antibody (ANA) and extractable nuclear antigen (ENA) positivity and mean UtA-PI were collected.
Results
A total of 1693 women had normal weight, 435 were overweight and 140 were obese. Maternal age, ANA/ENA positivity, history of autoimmune diseases and familiar history of thyroid diseases were similar in the three groups. TSH was significantly higher in obese women (1.8 (IQR: 1.4–2.4) mU/L) when compared to normal weight (1.6 (IQR: 1.2–2.2) mU/L) and overweight (median: 1.6 (IQR: 1.2–2.2) mU/L) ones (P < 0.001). BMI was significantly related with the risk of having a TSH level ≥4 mU/L at logistic regression, independently from non-thyroid autoimmunity, smoking or familiar predisposition for thyroid diseases (OR: 1.125, 95% CI: 1.080–1.172, P < 0.001). A restricted cubic splines regression showed a non-linear relationship between BMI and TSH. Women with a TSH ≥4 mU/L had a higher UtA-PI, independently from BMI.
Conclusion
Overweight/obesity is significantly related with TSH serum levels in AbTPO-negative pregnant women, independently from the other risk factors for hypothyroidism during pregnancy. The increase of TSH levels could be clinically relevant, as suggested by its association with abnormal UtA-PI, a surrogate marker of abnormal placentation.
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Department of Clinical Medicine, Aalborg University, Aalborg, Denmark
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Department of Clinical Medicine, Aalborg University, Aalborg, Denmark
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Objective
The physiological adaptations during a normal pregnancy affect renal and thyroid function and levels of associated biochemical markers. An association between cystatin C (CysC), creatinine, and thyroid function has been considered in nonpregnant individuals but not in pregnant women specifically.
Methods
Cohort study within the North Denmark Region Pregnancy Cohort (2011–2015) with assessment of thyroid function and autoantibodies (ADVIA Centaur XPT, Siemens Healthineers) in serum residues from the early pregnancy. Consecutive samples (n = 1112) were selected for measurement of CysC and creatinine (Atellica CH 930, Siemens Healthineers), and results were linked to information in Danish nationwide registers for (i) establishment of pregnancy-specific reference intervals for CysC and creatinine and (ii) evaluation of the prevalence of maternal hypothyroidism in early pregnancy according to levels of CysC and creatinine.
Results
The established reference intervals (2.5–97.5 percentiles) differed by week of pregnancy (week 4–8, 9–11, 12–15) and were CysC: 0.58–0.92 mg/L; 0.54–0.91 mg/L; 0.52–0.86 mg/L; creatinine: 46.9–73.0 µmol/L; 42.0–68.4 µmol/L; 38.8–66.4 µmol/L. The prevalence of maternal autoimmune hypothyroidism in early pregnancy differed by the level of CysC and creatinine (<25th percentile; 25th–75th percentile; >75th percentile) and was for CysC 1.7%, 3.8%, 7.4% and for creatinine 2.5%, 4.1%, 7.1%.
Conclusions
Reference intervals for CysC and creatinine were dynamic in early pregnancy and decreased with increasing gestational age. Furthermore, higher levels of CysC and creatinine associated with a higher prevalence of maternal autoimmune hypothyroidism. Results encourage considerations on the underlying mechanisms for the association between markers of renal and thyroid function.
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Objective
The aim of the study was to investigate the impact of suppressed serum TSH levels (sTSH) during early pregnancy on maternal and neonatal outcomes.
Methods
In this single-centre, retrospective cohort study 1081 women were screened at 11.8 ± 2.4 weeks of pregnancy for TSH, free T4 (FT4) and TPOAb. Exclusion criteria were twin- and assisted- reproduction pregnancies, women with TSH levels >3.74 mIU/L, severe hyperthyroidism, treated for thyroid dysfunction before or after screening and gestational blood sampling <6 or >16 weeks of pregnancy. The prevalence of adverse pregnancy outcomes was compared between the study group sTSH (TSH: < 0.06 mIU/L; n = 36) and euthyroid controls (TSH: 0.06–3.74 mIU/L; n = 1045), and the impact of sTSH on pregnancy outcomes verified in logistic regression analyses.
Results
Median (IQR) serum TSH level in women with sTSH was 0.03 (0.03–0.03) vs 1.25 (0.81–1.82) mIU/L in controls and FT4 levels 18.0 (14.4–20.3) vs 14.2 (12.9–15.4) pmol/L; both P < 0.001. None of the women with sTSH had thyrotropin receptor antibodies. Compared with controls, the prevalence of TPOAb positivity (TAI) was comparable between groups (5.6% vs 6.6%; P = 0.803). The prevalence of maternal and neonatal pregnancy outcomes was comparable between the study and control group. The logistic regression analyses with corrections for TAI, FT4 and demographic parameters confirmed the absence of an association between sTSH, and the following outcomes: iron deficient anaemia (aORs (95% CI)): 1.41 (0.64-2.99); P = 0.385, gestational diabetes: 1.19 (0.44–2.88); P = 0.713, preterm birth: 1.57 (0.23–6.22);P = 0.574 and low Apgar-1′ score: 0.71 (0.11–2.67); P = 0.657.
Conclusions
Suppressed serum TSH levels during the first to early second trimester of pregnancy were not associated with altered maternal or neonatal outcomes.
Institute for Health Science Research Germans Trias i Pujol (IGTP), Badalona, Spain
Department of Medicine, Autonomous University of Barcelona, Badalona, Spain
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Department of Obstetrics & Gynecology, Germans Trias i Pujol University Hospital, Badalona, Spain
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Health Department, Centre d’Estudis Epidemiològics sobre les Infeccions de Transmissió Sexual i Sida de Catalunya (CEEISCAT), Generalitat de Catalunya, Badalona, Spain
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Health Department, Centre d’Estudis Epidemiològics sobre les Infeccions de Transmissió Sexual i Sida de Catalunya (CEEISCAT), Generalitat de Catalunya, Badalona, Spain
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Institute for Health Science Research Germans Trias i Pujol (IGTP), Badalona, Spain
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Institute for Health Science Research Germans Trias i Pujol (IGTP), Badalona, Spain
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Health Department, Centre d’Estudis Epidemiològics sobre les Infeccions de Transmissió Sexual i Sida de Catalunya (CEEISCAT), Generalitat de Catalunya, Badalona, Spain
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Institute for Health Science Research Germans Trias i Pujol (IGTP), Badalona, Spain
Department of Medicine, Autonomous University of Barcelona, Badalona, Spain
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Objective
Longitudinal evaluation of thyroid function throughout pregnancy in the same subject could offer precise information about its dynamics as a physiological mechanism of adaption to the requirements. In this study, we evaluated longitudinal trajectories of maternal thyroid function during pregnancy by a latent class growth analysis and explored their association with maternal–fetal outcomes.
Methods
A prospective observational study was carried out, including 414 healthy pregnant women, from the first trimester to delivery. Thyroid function and autoimmunity were measured in the three trimesters. Clinical data during pregnancy were obtained. Longitudinal mixed model techniques were performed to explore trajectories of gestational thyroid function.
Results
Three different longitudinal trajectories were obtained from maternal thyrotropin (TSH) levels: low-increasing TSH (class 1) in 86% of cases, high-increasing TSH (class 2) in 9.7%, and decreasing TSH (class 3) in 4.3%. No statistical differences in free thyroxine levels were found among the three classes. Differences in maternal age (P = 0.027) and initial maternal weight (P = 0.043) were observed among the groups. In logistic regression analysis, maternal age correlated with longitudinal trajectories. The three longitudinal classes remain when women with thyroid autoimmunity (TAI) are excluded. Multinomial logistic regression showed maternal age correlated with longitudinal trajectories independently of TAI status.
Conclusions
Three differentiated TSH trajectories were found in healthy pregnant women living in Catalonia, as previously described. No association with obstetric outcomes was observed in these different chronological thyroid pathways, but maternal age might condition the longitudinal mechanism of thyroid function regulation throughout pregnancy.
Department of Clinical Medicine, Aalborg University, Aalborg, Denmark
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Department of Clinical Medicine, Aalborg University, Aalborg, Denmark
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Department of Clinical Medicine, Aalborg University, Aalborg, Denmark
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Department of Clinical Medicine, Aalborg University, Aalborg, Denmark
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Department of Clinical Medicine, Aalborg University, Aalborg, Denmark
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Department of Endocrinology, Aalborg University Hospital, Aalborg, Denmark
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Department of Endocrinology, Aalborg University Hospital, Aalborg, Denmark
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Department of Endocrinology, Aalborg University Hospital, Aalborg, Denmark
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Department of Endocrinology, Aalborg University Hospital, Aalborg, Denmark
Steno Diabetes Center North Jutland, Aalborg University Hospital, Aalborg, Denmark
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Department of Geriatrics, Aalborg University Hospital, Aalborg, Denmark
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Objective
Thyroid disease in women of reproductive age is mainly of autoimmune origin, and thyroid peroxidase antibodies (TPO-Ab) as well as thyroglobulin antibodies (Tg-Ab) are key markers. Adding to this, much focus in pregnancy is on euthyroid women who are thyroid antibody positive. Evidence to substantiate the cut-offs for the definition of thyroid autoantibody positivity in early pregnant women is warranted.
Methods
Stored serum samples from 14,030 Danish pregnant women were used for the measurement of TPO-Ab, Tg-Ab, TSH, and free thyroxine (ADVIA Centaur XPT, Siemens Healthineers). Among all women, a reference cohort of 10,905 individuals was identified for the establishment of antibody cut-offs. Percentile cut-offs for TPO-Ab and Tg-Ab were determined using regression on order statistics (the reference cohort). The established cut-offs were then applied (the full cohort), and frequencies of early pregnancy as well as later diagnosis of hypothyroidism were evaluated.
Results
The highest established cut-offs (95th, 97.5th, and 99th percentiles) were 59, 68, and 81 U/mL for TPO-Ab and 33, 41, and 52 U/mL for Tg-Ab. When the cut-offs were applied in the full cohort, 11.0, 10.2, and 9.7% were TPO-Ab positive, whereas 13.3, 12.3, and 11.2% were Tg-Ab positive. Antibody-positive women (TPO-Ab and/or Tg-Ab) had higher median TSH and were more likely to have hypothyroidism in early pregnancy and to be diagnosed with hypothyroidism during follow-up.
Conclusions
This large study established and evaluated pregnancy-specific cut-offs for TPO-Ab and Tg-Ab. The findings are important regarding the classification of exposure in pregnancy and assessment of thyroid autoimmunity per se.
Amsterdam Gastroenterology, Endocrinology & Metabolism, Amsterdam, The Netherlands
Department of Clinical Chemistry, Endocrine Laboratory, Amsterdam UMC location University of Amsterdam, Amsterdam, The Netherlands
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Amsterdam Reproduction & Development Research Institute, Amsterdam, The Netherlands
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Department of Clinical Chemistry, Endocrine Laboratory, Amsterdam UMC location University of Amsterdam, Amsterdam, The Netherlands
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Department of Clinical Chemistry, Endocrine Laboratory, Amsterdam UMC location University of Amsterdam, Amsterdam, The Netherlands
Amsterdam Reproduction & Development Research Institute, Amsterdam, The Netherlands
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Amsterdam Gastroenterology, Endocrinology & Metabolism, Amsterdam, The Netherlands
Department of Clinical Chemistry, Endocrine Laboratory, Amsterdam UMC location University of Amsterdam, Amsterdam, The Netherlands
Amsterdam Reproduction & Development Research Institute, Amsterdam, The Netherlands
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Objective
Thyroid hormone measurements are often performed in pregnant women, as hypo- and hyperthyroidism during pregnancy can severely affect the fetus. Serum free thyroxine (fT4) measurements are well known for their analytical challenges, due to low serum concentrations and the subtle equilibrium between free and bound T4 (to thyroid-binding globulin (TBG), transthyretin and albumin). Pregnant women have high TBG concentrations due to an increase in human chorionic gonadotropin (hCG) and estrogen and lower albumin concentrations which change the equilibrium and may affect the validity of fT4 measurements in their samples. As accurate serum fT4 measurements in pregnant women are important for the long-term health of the fetus, we aimed to evaluate the accuracy of several fT4 immunoassays in the serum of pregnant women.
Methods
FT4 was measured in healthy controls and pregnant women using a candidate-reference method (LC-MS/MS) and five commercially available automated immunoassays (Alinity (Abbott), Atellica (Siemens), Cobas (Roche), Lumipulse (Fujirebio) and UniCel DXI (Beckman Coulter)). Method comparisons (Bland Altman plots and Passing and Bablok analyses) were performed.
Results
Serum samples from both healthy controls (n = 30) and pregnant women (n = 30; mean gestational age, 24.8 weeks) were collected. The fT4 immunoassays deviated +7 to +29% more from the LC-MS/MS in serum samples of pregnant women than healthy controls (falsely high).
Conclusions
Our results indicate that immunoassays overestimate fT4 in pregnant women, which might lead to an overestimation of thyroid status. Physicians and laboratory specialists should be aware of this phenomenon to avoid drawing false conclusions about thyroid function in pregnant women.
