Reference Ranges and Determinants of Thyroid Function and TSH Receptor Antibodies During Early Pregnancy in Nepal.

Objective: Different definitions of thyroid dysfunction during pregnancy may lead to under or overtreatment. The aims of this study were to (1) define population-based pregnancy-specific reference ranges for thyroid dysfunction during early pregnancy in Nepal and assess the impact of antibody positivity, (2) quantify the diagnostic impact of population-based reference ranges compared with current practice and (3) assess the determinants of thyroid function and antibody positivity.

Methods: A total of 800 healthy pregnant women aged 20-40 years in the Bhaktapur municipality were included.

Association of maternal thyroglobulin with gestational thyroid function and offspring IQ and brain morphology.

Background: Low maternal urinary iodine concentration (UIC) during pregnancy is associated with adverse offspring neurodevelopment. Thyroglobulin (Tg) has been suggested as a more sensitive biomarker than UIC of long-term iodine status, but associations of Tg with neurodevelopment and the possible mediating role of thyroid function remain unknown.

Aim: To study whether maternal Tg is associated with i) maternal and newborn thyroid function and ii) offspring IQ and brain morphology.

Defining Gestational Thyroid Dysfunction Through Modified Nonpregnancy Reference Intervals: An Individual Participant Meta-analysis.

Background: Establishing local trimester-specific reference intervals for gestational TSH and free T4 (FT4) is often not feasible, necessitating alternative strategies. We aimed to systematically quantify the diagnostic performance of standardized modifications of center-specific nonpregnancy reference intervals as compared to trimester-specific reference intervals.

Methods: We included prospective cohorts participating in the Consortium on Thyroid and Pregnancy.

Predictors of treatment response in lymphogenic metastasized papillary thyroid cancer: a histopathological study.

Background: Lymph node metastases in papillary thyroid cancer (PTC) increase the risk for persistent and recurrent disease. Data on the predictive value of histopathological features of lymph node metastases, however, are inconsistent. The aim of this study was to evaluate the prognostic significance of known and new histopathological features of lymph node metastases in a well-defined cohort of PTC patients with clinically evident lymph node metastases.

Association between per- and polyfluoroalkyl substances exposure and thyroid function biomarkers among females attending a fertility clinic.

Per- and polyfluoroalkyl substances (PFAS) exposure was associated with changes in thyroid function in pregnant mothers and the general population. Limited such evidence exists in other susceptible populations such as females with fertility problems. This cross-sectional study included 287 females seeking medically assisted reproduction at a fertility clinic in Massachusetts, United States, between 2005 and 2019.

Iodineminho Study: Iodine Supplementation and Prevalence of Iodine Deficiency In Pregnant Women.

Context: Iodine is necessary for proper brain development. The prevalence of iodine deficiency in Portuguese pregnant women led the health authorities, in 2013, to recommend iodine supplementation for women in preconception, throughout pregnancy, and during lactation.

Objective: This work aimed to assess the effect of iodine supplementation initiated in the preconception or the first trimester of pregnancy on the prevalence of iodine deficiency and maternal thyroid status.

The optimal healthy ranges of thyroid function defined by the risk of cardiovascular disease and mortality: systematic review and individual participant data meta-analysis.

Background: Reference intervals of thyroid-stimulating hormone (TSH) and free thyroxine (FT) are statistically defined by the 2·5-97·5th percentiles, without accounting for potential risk of clinical outcomes. We aimed to define the optimal healthy ranges of TSH and FT based on the risk of cardiovascular disease and mortality.

Methods: This systematic review and individual participant data (IPD) meta-analysis identified eligible prospective cohorts through the Thyroid Studies Collaboration, supplemented with a systematic search via Embase, MEDLINE (Ovid), Web of science, the Cochrane Central Register of Controlled Trials, and Google Scholar from Jan 1, 2011, to Feb 12, 2017 with an updated search to Oct 13, 2022 (cohorts found in the second search were not included in the IPD).

Genetic determinants of thyroid function in children.

Objective: Genome-wide association studies in adults have identified 42 loci associated with thyroid stimulating hormone (TSH) and 21 loci associated with free thyroxine (FT4) concentrations. While biologically plausible, age-dependent effects have not been assessed. We aimed to study the association of previously identified genetic determinants of TSH and FT4 with TSH and FT4 concentrations in newborns and (pre)school children.

Association of endocrine disrupting chemicals exposure with human chorionic gonadotropin concentrations in pregnancy.

Background: Human chorionic gonadotropin (hCG) is produced by the placenta and plays an essential role in the maintenance of pregnancy. Endocrine disrupting chemicals (EDCs) have the potential to interfere with functions related to the production and secretion of hCG; however associations between exposure to EDCs and hCG concentrations in humans remain to be elucidated.

Objectives: To investigate the association of urinary, serum and plasma concentrations of EDCs during pregnancy with serum hCG concentrations.

Associations of Maternal Urinary Concentrations of Phenols, Individually and as a Mixture, with Serum Biomarkers of Thyroid Function and Autoimmunity: Results from the EARTH Study.

The associations between urinary phenol concentrations and markers of thyroid function and autoimmunity among potentially susceptible subgroups, such as subfertile women, have been understudied, especially when considering chemical mixtures. We evaluated cross-sectional associations of urinary phenol concentrations, individually and as a mixture, with serum markers of thyroid function and autoimmunity. We included 339 women attending a fertility center who provided one spot urine and one blood sample at enrollment (2009-2015).

Exploration of thyroglobulin as a biomarker of iodine status in iodine-sufficient and mildly iodine-deficient pregnant women.

Purpose: Urinary iodine-to-creatinine ratio (UI/Creat) reflects recent iodine intake but has limitations for assessing habitual intake. Thyroglobulin (Tg) concentration, which increases with thyroid size, appears to be an indicator of longer-term iodine status in children and adults, however, less is known in pregnancy. This study investigated the determinants of serum-Tg in pregnancy and its use as an iodine-status biomarker in settings of iodine-sufficiency and mild-to-moderate deficiency.

Triglycerides Mediate the Relationship Between Maternal Free Thyroxine and Birth Weight: A Prospective Cohort Study from China.

Fetal overgrowth (large for gestational age, LGA) is associated with an increased risk of maternal and fetal morbidity and adverse health outcomes. Thyroid hormones are key regulators of metabolism during pregnancy and fetal development. Lower maternal free thyroxine (fT4) and higher maternal triglyceride (TG) levels during early pregnancy are associated with higher birth weight.

Reference ranges of anti-Müllerian hormone and interaction with placental biomarkers in early pregnancy: the Generation R Study, a population-based prospective cohort study.

Objective: The primary objective of this study is to establish maternal reference values of anti-Müllerian hormone (AMH) in a fertile multi-ethnic urban pregnant population and to evaluate the effect of gestational age. The secondary objective of this study is to explore the association between AMH and placental biomarkers.

Design: This study was embedded in the Generation R Study, an ongoing population-based prospective cohort study from early pregnancy onwards.

Effect of intensive care unit-specific virtual reality (ICU-VR) to improve psychological well-being in ICU survivors: study protocol for an international, multicentre, randomised controlled trial-the HORIZON-IC study.

Introduction: A substantial proportion of intensive care unit (ICU) survivors develop psychological impairments after ICU treatment, part of the postintensive care syndrome, resulting in a decreased quality of life. Recent data suggest that an ICU-specific virtual reality intervention (ICU-VR) for post-ICU patients is feasible and safe, improves satisfaction with ICU aftercare, and might improve psychological sequelae. In the present trial, we firstly aim to determine whether ICU-VR is effective in mitigating post-traumatic stress disorder (PTSD)-related symptoms and secondly to determine the optimal timing for initiation with ICU-VR.

Association of per- and polyfluoroalkyl substances with thyroid homeostasis during pregnancy in the SELMA study.

Objectives: To investigate the association of exposure to per- and polyfluoroalkyl substances (PFAS) during early pregnancy with markers of the maternal thyroid system.

Methods: Serum concentrations of seven PFAS as well as thyroid stimulating hormone (TSH), free and total thyroxine (FT4 and TT4), free and total triiodothyronine (FT3 and TT3) were measured in pregnant women in early pregnancy in the Swedish Environmental Longitudinal, Mother and child, Asthma and allergy (SELMA) study. Outcomes were concentrations of TSH and thyroid hormones, FT4/FT3 or TT4/TT3 ratios, TSH/FT4 ratio as a marker of the negative feedback loop, TT4/FT4 or TT3/FT3 ratios as markers of the binding of thyroid hormones to binding proteins.

TSH and FT4 Reference Intervals in Pregnancy: A Systematic Review and Individual Participant Data Meta-Analysis.

Context: Interpretation of thyroid function tests during pregnancy is limited by the generalizability of reference intervals between cohorts due to inconsistent methodology.

Objective: (1) To provide an overview of published reference intervals for thyrotropin (TSH) and free thyroxine (FT4) in pregnancy, (2) to assess the consequences of common methodological between-study differences by combining raw data from different cohorts.

Methods: (1) Ovid MEDLINE, EMBASE, and Web of Science were searched until December 12, 2021.

Euthyroid Thyroperoxidase Antibody Positivity during Pregnancy, to Treat or Not to Treat?

Thyroperoxidase antibody (TPOAb) positivity is a well-known risk factor for thyroid dysfunction during pregnancy and is associated with a suboptimal response to thyroidal stimulation by human chorionic gonadotropin. About 75% of TPOAb positive women are euthyroid and there seems to be a higher risk of predominantly miscarriage and preterm birth in this subgroup. Nonetheless, clinical decision making with regards to gestational levothyroxine treatment remains difficult due to a lack of large randomized trials.

Binding Characteristics of Thyroid Hormone Distributor Proteins to Thyroid Hormone Metabolites.

In contrast to the thyroid hormones (THs) 3,3',5-triiodothyronine (T3) and 3,3',5,5'-tetraiodothyronine (thyroxine or T4), the binding characteristics of the thyroid hormone distributor proteins (THDP), thyroxine-binding globulin (TBG), albumin, and transthyretin in relation to TH metabolites are mostly lacking. In this study, we determined the distribution and binding affinity of TH metabolites to THDP, which is important for adequate interpretation of TH metabolite concentrations. Distribution of I-3,3'-diiodothyronine (3,3'-T2), -T3, -3,3',5'-triiodothyronine (rT3), -3,3',5-triiodothyroacetic acid (TA3), and -3,3',5,5'-tetraiodothyroacetic acid (TA4) to TBG, transthyretin, and albumin was determined by agar gel electrophoresis.