isolated hypothyroxinemia

OBJECTIVES: Childhood obesity and iodine deficiency are global public health concerns. Whether maternal iodine status mediates overweight in infancy has yet to be explored. We aimed to assess the relationship between maternal iodine status and infant birth weight, including small and large for gestational age (SGA and LGA, respectively). METHODS: A prospective study was carried out among 134 mother-infant pairs from Israel. Maternal iodine intake and status were estimated via questionnaire and serum thyroglobulin (Tg), respectively...

PURPOSE: There are conflicting results about the effects of maternal hypothyroidism (IMH) on adverse pregnancy outcomes. This study aimed to investigate the relationship between IMH identified in the first trimester of gestation and adverse pregnancy outcomes. METHODS: In this prospective cohort study, we used data from the Tehran Thyroid and Pregnancy study (TTPs). To diagnose IMH, we considered a threshold of 2.04 for FTI, which was based on the 10th percentile of this marker identified in the 1st trimesters...

BACKGROUND: The outbreak of COVID-19 epidemic has induced entire cities in China placed under 'mass quarantine'. The majority of pregnant women have to be confined at home may be more vulnerable to stressors. In our study, we aimed to explore the effects of the epidemic on maternal thyroid function, so as to provide evidence for prevention and intervention of sustained maternal and offspring's health impairment produced by thyroid dysfunction. METHODS: The subjects were selected from an ongoing prospective cohort study...

OBJECTIVE: To estimate the association of maternal thyroid dysfunction with the risk of gestational hypertension and diabetes. Whether the association was affected by gestational age at diagnosis and thyroid autoimmunity was further explored. METHODS: A cohort study of 41 647 participants was conducted. Thyroid function (ie, thyroid-stimulating hormone [TSH] and free thyroxine [FT4]) was measured by electrochemiluminescence immunoassay. Thyroid antibody positivity (eg, thyroperoxidase, thyroglobulin, and TSH receptor antibody) was indicated if the values of these antibodies exceeded the upper targets of the reference range...

Thyroid diseases in pregnancy are common. While data on management of overt diseases are clear, there is no consensus regarding subclinical thyroid disease. Many studies have tried to clarify the impact of subclinical thyroid disease on pregnancy outcomes without reaching universal conclusions. As several studies are present in literature, but no univocal indication is present to manage each condition, the present review tries to summarize the recent indications for such disease. The most updated guidelines are 2017 American thyroid association for thyroid disease during pregnancy, which at present represent the most accurate and reliable guide...

CONTEXT: Prepregnancy overweight/obesity (OWO) and isolated maternal hypothyroxinemia (IMH) may increase the risk of macrosomia, but little is known about their potential combined effect on macrosomia. OBJECTIVE: The aim of this study was to assess whether prepregnancy OWO and first-trimester IMH have a synergistic effect on the risk of macrosomia. METHODS: A large prospective cohort study in a Chinese population from January 2016 to December 2018 in a tertiary care center...

BACKGROUND: Although Iran has been considered iodine replete since 2000, the first national survey of iodine intake among Iranian pregnant women in 2014 indicated that despite the adequate intake of iodine by the general population, this vulnerable group has moderate iodine deficiency. Therefore, in this national cross-sectional interventional study, we aimed to assess the iodine intake and thyroid function of Iranian pregnant women 2 years after implementing national iodine supplementation for this vulnerable group...

Maternal thyroid hormones are vital for a normal pregnancy and the development of fetus and childhood; inadequate availability of thyroid hormones during pregnancy is associated with adverse pregnancy outcomes. Isolated maternal hypothyroxinemia (IMH) is defined as a low maternal T4 in the absence of TSH elevation. This systematic review aimed to investigate the association between IMH and adverse pregnancy outcomes. PubMed, Scopus and Web of science were searched for retrieving observational studies published up to September 2020, investigating the association of IMH with adverse pregnancy outcomes...

Purpose: COVID-19 (Coronavirus Disease 2019) was first reported in December 2019 and quickly swept across China and around the world. Levels of anxiety and depression were increased among pregnant women during this infectious pandemic. Thyroid function is altered during stressful experiences, and any abnormality during early pregnancy may significantly affect fetal development and pregnancy outcomes. This study aimed to determine whether the COVID-19 pandemic induces thyroid hormone changes in early pregnant women...

BACKGROUND: The management of subclinical hypothyroidism (SCH) and thyroid autoimmunity (TAI) in pregnancy is still uncertain. Over the years, several scientific societies published guidelines on the management of thyroid dysfunction before, during, and after pregnancy, the most recent ones being published by the American Thyroid Association (ATA) in 2017. OBJECTIVE: This study aimed to review the published literature in the field since 2017 onward to investigate whether new findings can change ATA recommendations...

Objective: Adverse maternal outcomes and perinatal complications are associated with overt and subclinical maternal hypothyroidism. It is not clear whether these complications also occur in women with isolated hypothyroxinemia during pregnancy. The aim of this study was to evaluate the effects of isolated hypothyroxinemia on maternal and perinatal outcomes during pregnancy. Methods: This study included data from 2,864 pregnant women in the first trimester (67 women with isolated hypothyroxinemia, 784 euthyroid women) and the second trimester (70 women with isolated hypothyroxinemia, 1,943 euthyroid women) of pregnancy...

Thyroid hormones are essential for maintaining a pregnancy and optimal fetal neurological development. Pregnancy places additional demands on the thyroid axis and around 5% of women who have their thyroid function checked during gestation will have borderline low thyroid function (subclinical hypothyroidism or isolated hypothyroxinemia) identified. These borderline low thyroid states are associated with adverse obstetric and offspring outcomes. Whilst it is well established that overt hypothyroidism requires treatment with levothyroxine, it is less clear whether there is any benefit of treating borderline low thyroid states...

BACKGROUND: Total T4 (TT4) measurement is preferred to free T4 (FT4) especially in last part of pregnancy. Guidelines by American Thyroid Association, European Thyroid Association and Endocrine Society state that TT4 increases 1.5 times pre-pregnant levels after week 16 of pregnancy. However, this is based on a small study conducted 40 years ago which used radioimmunoassay for determination in changes in TT4. MATERIALS AND METHODS: A cross-sectional study was undertaken to find reference interval for thyroid function in different trimester of pregnancy with special reference to look at the degree of elevation of TT4 as compared to non-pregnant women...

Background: Compared with singletons, a twin pregnancy is associated with a larger thyroid hormone demand and an increased stimulation of gestational thyroid function due to higher concentrations of human chorionic gonadotropin. However, such effects have been sparsely quantified. The aim of this study was to evaluate thyroid function and thyroid function test abnormalities in twin pregnancies during early and late pregnancy compared with singletons. Methods: We included 1208 twin pregnancies and 46,834 singleton pregnancies with thyroid function tests available...

Little is known about iodine adequacy and gestational thyroid disorders (GTDs) in Saudi Arabia. This study measured the rates of GTDs and iodine adequacy in 810 healthy Saudi women. Concentrations of serum thyroid hormones and 24-h urine iodine (24-h UIC), and GTDs were diagnosed according to the American Thyroid Association guidelines. Dietary and socioeconomic data to determine factors associated with GTDs and iodine insufficiency were collected. GTDs were detected in 265 women (32.7%) as follows: subclinical (SCH; 20...

Background: The association between isolated maternal hypothyroxinemia (IMH) during pregnancy and preterm birth (PTB), especially for subtypes of PTB, is unclear. This study aimed at determining the association between IMH diagnosed in early pregnancy and PTB, with further investigation into various subtypes of PTB. Methods: This study included 41,911 pregnant women (963 with IMH and 40,948 euthyroid women) who underwent first-trimester prenatal screening at the International Peace Maternity and Child Health Hospital (IPMCH) in Shanghai, China between January 2013 and December 2016...

Many changes occur in the physiology of the maternal thyroid gland to maintain an adequate level of thyroid hormones (THs) at each stage of gestation during normal pregnancy, however, some factors can produce low levels of these hormones, which can alter the onset and progression of pregnancy. Deficiency of THs can be moderate or severe, and classified as overt or clinical hypothyroidism, subclinical hypothyroidism, and isolated hypothyroxinemia. Overt hypothyroidism has been reported in 0.3-1.9% and subclinical hypothyroidism in approximately 1...

Background: Thyroid disorders such as subclinical hypothyroidism and isolated maternal hypothyroxinemia are understudied in pregnant women, despite their possible adverse effects on the health of mother and child. Also, the role of iodine deficiency in developing such disorders has not yet been fully understood. Methods: The present national population-based cross-sectional study was conducted on 1080 randomly recruited pregnant women, aged 20-40 from 12 provinces of Iran from 2013 to 2014. Serum concentrations of thyrotropin, T4, thyroid peroxidase antibody (TPOAb), and triiodothyronine (T3) resin uptake values were measured in fasting blood samples, and urinary iodine concentration (UIC) was measured in three separate urine samples...

This article aims to understand the isolated effect of maternal thyroid-stimulating hormone (TSH), free thyroxine (FT4 ) and antithyroid peroxidase antibodies (TPOAb) in early pregnancy on gestational diabetes mellitus (GDM). Based on a birth cohort, pregnant women presented to maternity hospitals for the first antenatal care from Nov 2008 to Oct 2010 were invited to participate in the study. A self-administered questionnaire was asked to complete to collect data on socio-economic variables, previous adverse pregnancy outcomes, method of conception, previous endocrinic and metabolic diseases, and pregnancy-related anxiety in 1st trimester of the index pregnancy...

Objectives: Pregnancy induces changes in thyroid function, and thyroid dysfunction during gestation is associated with adverse outcomes. We examined the management of subclinical hypothyroidism and chronic autoimmune thyroiditis in pregnancy among Italian and Romanian endocrinologists. Methods: Members of the Associazione Medici Endocrinologi (AME) and Romanian Society of Endocrinology (RSE) were invited to participate in a web-based survey investigating the topic...