Graves' hyperthyroidism in pregnancy: a clinical review

Management Aspects of Medical Therapy in Graves Disease

OBJECTIVE

Graves disease (GD) is the most common cause of hyperthyroidism. Treatment options include antithyroid drugs (ATDs), radioactive iodine, and surgery. In this review, we focus on the medical aspects of managing GD.

METHODS

The authors conducted a literature review of PubMed to include studies and review articles on GD management, ATDs, long-term safety of antithyroid drugs, hyperthyroidism in pregnancy, Graves ophthalmopathy, and special circumstances related to hyperthyroidism.

RESULTS

In adjunction to ATDs, medical management for GD also includes beta-blockers, glucocorticoids, and iodine containing agents. ATDs are currently the preferred option for initial management of GD, reflecting a shift in practice observed in the United States over the past 2 decades. ATDs in appropriate doses are well-tolerated and safe when used for longer duration, during pregnancy, and other circumstances discussed in this article. Routine thyroid function tests are important for monitoring. Thyrotropin receptor antibody plays an essential role in determining duration of treatment and assessing the likelihood of recurrence.

CONCLUSION

Medical management of GD with antithyroid drug is safe and effective. Long-term use beyond 24 months in patients with elevated thyrotropin receptor antibody is a reasonable alternative option to surgery and radioactive iodine due to higher rates of remission.

Narrative review of pediatric thyroiditis: Diagnosis and management

OBJECTIVE

To the best of the authors' knowledge, no current literature reviews on pediatric thyroiditis exist. Our aim is to present relevant and updated information on pediatric thyroiditis subtypes and presentations.

DATA SOURCES

A narrative review was performed using PubMed and Embase.

REVIEW METHODS

A narrative literature review was performed to find articles in two databases: PubMed and Embase that discussed the various subtypes of thyroiditis in pediatric patients. Relevant key terms included: thyroiditis, pediatric, children, clinical findings, autoimmune thyroiditis, prevalence, and etiology.

DISCUSSION

112 articles were included in this review. The subtypes and clinical presentations of pediatric thyroiditis were highlighted to demonstrate that thyroid dysfunction can have unique wide-ranging effects compared to adult populations. Recommendations on diagnostic algorithms, management, and clinical consequences of delayed treatment are discussed.

CONCLUSIONS

Thyroid hormones are incredibly vital to the development of a child. It is important to identify and prevent long-term consequences clinically by implementing early treatment through awareness of these differences in clinical practice.

Hyperthyroidism in a Twin Pregnancy With a Hydatidiform Mole and a Coexisting Live Fetus: Management Dilemmas

Hyperthyroidism in twin pregnancies involving a hydatidiform mole and a coexisting live fetus is a rare condition requiring careful management. We present a 34-year-old pregnant woman at 12 weeks' gestation with severe nausea, vomiting, and mild vaginal bleeding. A transvaginal ultrasound revealed a dichorionic diamniotic twin pregnancy with 1 normal fetus and 1 hydatidiform mole, leading to hyperthyroidism from elevated β human chorionic gonadotropin levels. Conservative management without antithyroid medications, combined with regular monitoring, allowed the pregnancy to continue to term, resulting in the delivery of a healthy baby at 39 weeks. Postpartum management required treatment of retained products of conception. This case highlights the complexities in the management of complications for both mother and fetus.

An Unusual and Severe Thyrotoxicosis in a Twin Pregnancy: Fortune Favors the Brave

Graves' disease (GD) and gestational transient thyrotoxicosis (GTT) are the most common causes of thyrotoxicosis during pregnancy, with prevalence ranging from 0.1% to 1% and from 1% to 3%, respectively. Hyperthyroidism during pregnancy can have severe consequences if not promptly recognized and treated. Even more severe, if possible, is the thyroid storm, a life-threatening complication of hyperthyroidism, characterized by severe and dramatic clinical manifestations of thyrotoxicosis. No prior history of thyroid disease, absence of GD stigmata, negative thyrotropin (TSH) receptor antibody levels, serum human chorionic gonadotropin (hCG) higher on average, and symptoms of emesis may lead to the diagnosis of GTT. Few cases of thyroid storm during pregnancy are reported in literature, mainly due to gestational trophoblastic disease. We report a rare and severe case of thyroid storm in a 24-year-old woman at 15 weeks' gestation with twins, likely due to GTT, precipitated by acute myocarditis. Initially presenting with weakness, vomiting, and sinus tachycardia, the patient rapidly deteriorated into a life-threatening condition characterized by hypokalemia, myocardial injury, and severe thyrotoxicosis. Cardiac imaging later revealed acute myocarditis. Thyroid function stabilized at the end of the pregnancy, allowing discontinuation of methimazole. Both fetuses were delivered via emergency cesarean section at 36 weeks, with no significant congenital abnormalities. This case highlights the complexity of diagnosing and managing hyperthyroidism in twin pregnancies, particularly in the context of hyperemesis gravidarum (HG).

Best practices in the laboratory diagnosis, prognostication, prediction, and monitoring of Graves' disease: role of TRAbs

Graves' disease (GD) is an autoimmune disorder characterized by activation of the TSH receptor by stimulatory autoantibodies (TSH Receptor Antibodies, or TRAbs), leading to unregulated thyroid hormone production. Diagnosis is largely based on the typical clinical picture and laboratory thyroid panel. Establishment of elevated serum levels of TRAbs by competitive binding assay or cell-binding assay has its unique role in diagnosis and management of GD, especially in the differential diagnosis, therapy selection, prognostication, evaluation of thyroid function during pregnancy, peri-conceptional and neonatal thyroid workup, and in certain special situation. Inclusion of TRAbs in GD diagnostic algorithm can improve cost-effectiveness of GD management. The current best practice guidelines were developed to provide evidence-based recommendations in the use of TRABs in GD management for healthcare providers in South Asia. A panel of endocrinologists with minimum 10 years of clinical experience in thyroid disorders reviewed existing literature and their quality, and after deliberation and discussion, developed 21 recommendations surrounding the best practices surrounding the role of TRAbs in GD management.

Neonatal Thyrotoxicosis in Infants of Mothers with Graves' Disease Treated for Radioiodine-Induced Hypothyroidism: A Literature Review

Fetal and neonatal thyrotoxicosis occurs in up to 5% of pregnancies in mothers with Graves' disease (GD). This condition is caused by stimulating antibodies against the thyrotropin receptor (TRAbs) that cross the placenta and may stimulate the fetal thyroid, typically in the second half of pregnancy. GD is often treated with radioiodine, resulting in hypothyroidism in most patients, but TRAbs can persist for several years. Even if a pregnant mother is hypothyroid after radioiodine therapy or surgery, her TRAbs can still, although rarely, induce fetal hyperthyroidism. In this review, we first present two cases of neonatal hyperthyroidism in mothers with GD who became hypothyroid after prior radioiodine therapy, identified through a 10-year analysis of the National Perinatal System in Slovenia. Based on these cases, we provide an overview of existing data on this rare clinical condition in neonates. We also discuss the underlying mechanisms and clinical outcomes based on currently available data. In conclusion, our review highlights the importance of careful monitoring during pregnancy in all women with GD, even in those well managed after radioiodine therapy or surgery.

Clinical features of neonatal hyperthyroidism: a retrospective analysis in southwestern China

Purpose

This study aimed to explore the clinical characteristics and evaluate the different types of thyroid dysfunction in babies with neonatal hyperthyroidism.

Methods

The clinical data of 19 neonates with hyperthyroidism admitted to the Children's Hospital of Chongqing Medical University between January 2012 and April 2021 were retrospectively analyzed.

Results

Fifteen (78.9%) infants were born to mothers with Graves' disease. Eleven (57.9%) infants were premature; two babies were born at small for gestational age. The age at diagnosis ranged from 3 to 34 days, with a mean of 18.53 ± 6.85 days. The majority of the babies presented with goiter (84.2%) and tachycardia (94.7%) after birth. Nine (47.4%) of them presented with abnormal weight gain, seven (36.8%) presented with stare or ocular protrusion, six (31.6%) presented with hyperexcitability, four (21.1%) presented with jaundice and liver dysfunction, two (10.5%) presented with sweating, one (5.3%) presented with fever, and one case presented without any symptoms. Transient hyperthyroidism was the main thyroid dysfunction in our study. Overt hyperthyroidism was diagnosed in 13 (68.4%) neonates. Another three babies (15.8%) presented with hyperthyroidism with slightly elevated free triiodothyronine levels, normal thyroxine (T4) levels, and low thyroid-stimulating hormone (TSH) levels. Normal thyroid hormone levels with low TSH levels were observed in three (15.8%) neonates. Ten children were treated with antithyroid drugs. Eighteen children recovered normal thyroid function at 1-3 months of age; one baby in the study group required further levothyroxine supplementation due to primary hypothyroidism (HT). One child was found to have developmental delay at 2 years of age during follow-up.

Conclusions

Our study highlights the need for prolonged monitoring of thyroid function in suspected patients. A single normal screening for hyperthyroidism or the absence of a maternal history of hyperthyroidism cannot exclude this disease.

Management of fetal hyperthyroidism caused by persistent autoimmune antibodies in a case of previously treated maternal Graves' disease

Maternal Graves' autoantibodies are well known to cause fetal and neonatal thyroid disturbances. Despite radioiodine therapy, Graves' autoantibodies are known to persist, which can cross the placenta and cause hyperthyroidism in the fetus. We present the case of a 26-year-old woman in her first pregnancy, clinically and biochemically euthyroid with history of treated Graves' disease, where the fetus showed signs of hyperthyroidism on antenatal scans. This was confirmed by amniotic fluid testing as fetal blood sampling was not feasible and successfully treated with maternal carbimazole whilst continuing thyroxine for the mother (block-replacement). We discuss the challenges in the diagnosis of fetal hyperthyroidism and treatment whilst maternal thyroid status is maintained on thyroxine.

Maternal Graves Disease Postthyroidectomy With Fetal Thyrotoxicosis and Goiter

Fetal thyrotoxicosis is a rare condition with high morbidity and mortality. It may complicate pregnancies in women with a history of Graves disease (GD) when transplacental passage of maternal TSH receptor antibodies stimulate the fetal thyroid gland and cause hyperthyroidism. We report the case of a 34-year-old woman with a history of GD and prior thyroidectomy, where fetal thyrotoxicosis at 21 weeks of gestation was suspected due to prenatal ultrasound findings of cardiac failure and fetal goiter. She was treated with high-dose carbimazole and followed closely by a multidisciplinary team. Her baby was delivered in good condition at 34 weeks' gestation and developed hyperthyroidism in the days after birth, which was successfully treated medically. This case highlights the importance of awareness of the condition among women with a history of GD, as well as the necessity for prompt diagnosis and treatment of this complex disease.

Pregnancy and the eye: What do we need to watch out for? A review

Pregnancy causes changes in all body systems, including the eye. The eye can undergo physiological and pathological changes in pregnancy. Some changes exacerbate pre-existing eye conditions while other conditions manifest for the first-time during pregnancy. Early recognition and management are essential to prevent sight threatening complications. In addition, some obstetric complications can be associated with ophthalmic signs. Prompt recognition of these eye findings may be life saving for both the mother and the foetus. The aim of this article is to present potential ocular complications in pregnancy and outline the appropriate management to preserve sight and maintain maternal and foetal safety. The safety of the use of common ophthalmological medications will also be discussed.

Autoimmune Thyroid Diseases

Autoimmune thyroid diseases (AITDs) include a wide spectrum of thyroid diseases affecting more commonly women than men. The most frequent forms are Graves' Disease (GD) and Hashimoto's thyroiditis / Autoimmune Thyroiditis (AIT), but there are also other immunogenic destructive forms of thyroiditis, that is, silent and postpartum thyroiditis. In the last decade, AITDs and other inflammatory thyroid diseases related to anti-tumor molecular drugs are more frequently seen due to the widespread use of tyrosine kinase inhibitors (TKIs) and immune checkpoint inhibitors (ICPIs). Autoimmune thyroiditis related to SARS-CoV-2 infection has been a novel entity in recent years. Graves' Disease and AIT may shift from hyperthyroidism to hypothyroidism, which may complicate the differential diagnosis and further treatment strategy. Moreover, all AITDs may manifest with thyrotoxicosis (a clinical condition marked with high serum levels of thyroid hormones) which has to be distinguished from hyperthyroidism (increased thyroid hormone production and secretion as a result of hyperfunctioning thyroid gland) due to different therapeutic approaches. Nuclear medicine techniques, such as radioiodine uptake (RAIU) and thyroid scintigraphy, using 99mTc- pertechnetate (Na[99mTc]TcO4) or 123-Iodine (Na[123I]I), have a crucial role in the differential diagnosis. Measurement of thyroid antibodies, e.g. thyroid peroxidase antibodies (TPO) and thyrotropin receptor antibodies (TRAb), as well as thyroid ultrasound, are complementary methods in the evaluation of thyroid disorders.

[Guideline for Radioiodine Therapy for Benign Thyroid Diseases (6/2022 - AWMF No. 031-003)]

This version of the guideline for radioiodine therapy of benign thyroid disorders is an update of the version, which was published by the German Society of Nuclear Medicine (Deutsche Gesellschaft für Nuklearmedizin, DGN) in co-ordination with the German Society of Endocrinology (Deutsche Gesellschaft für Endokrinologie, DGE, Sektion Schilddrüse) and the German Society of General- and Visceral-Surgery (Deutsche Gesellschaft für Allgemein- und Viszeralchirurgie, DGAV) in 2015. This guideline was harmonized with the recommendations of the European Association of Nuclear Medicine (EANM). According to the German "Directive on Radiation Protection in Medicine" the physician specialised in nuclear medicine ("Fachkunde in der Therapie mit offenen radioaktiven Stoffen") is responsible for the justification to treat with radioiodine. Therefore, relevant medical indications for radioiodine therapy and alternative therapeutic options are discussed within the guideline. This procedure guideline is developed in the consensus of an expert group. This fulfils the level S1 (first step) within the German classification of Clinical Practice Guidelines.

Association of vitamin A with gestational diabetes and thyroid disorders in pregnancy and their influence on maternal, fetal, and neonatal outcomes

Gestational diabetes mellitus (GDM) and thyroid disorders during pregnancy pose significant health concerns, impacting a substantial number of mothers globally. Globally, about 14% of pregnant women develop GDM, while thyroid disorders impact approximately 2%-3%. Both conditions contribute to adverse outcomes, including gestational hypertension, excessive fetal growth, and heightened perinatal morbidity. The central focus of this literature review is to examine the relationship between vitamin A, a crucial fat-soluble micronutrient in fetal development, and the occurrence of GDM and thyroid disorders during pregnancy. The primary research question investigates the association between vitamin A, GDM, and thyroid disorders, analyzing their combined impact on maternal, fetal, and neonatal outcomes. The review underscores the potential of vitamin A to modulate the risk and outcomes of GDM and thyroid disorders during gestation, emphasizing its role in GDM development and resolution and its influence on thyroid function in pregnancy.

A Case of Aplasia Cutis Congenita in the Setting of Maternal Carbimazole Use in the First Trimester

Aplasia cutis congenita (ACC) is one of several congenital malformations associated with antithyroid/thiourylene drug use in pregnancy. While uncommon among the general population (1-3/100 000 cases), the risk among those on thiourylenes is between 1.6% and 3%. The scalp is the most common site for this congenital anomaly. We present the case of a male infant with multifocal ACC of the scalp discovered at birth and born to a mother with Graves disease that was controlled during pregnancy using carbimazole. Thyroid function tests were normal throughout the pregnancy. There was no involvement of underlying subcutaneous tissue or structures. At age 18 months, the single largest lesion remained with only partial coverage. Prospective management involved periodic surveillance with planned 2-stage repair. This case reinforces the association between the antithyroid drugs carbimazole (CMZ) and methimazole (MMI) and supports the proposition of an MMI/CMZ embryopathy. It adds to a literature of case reports in which malformations arise in offspring of such mothers whose thyrotoxicosis is controlled antenatally, thereby challenging the suggestion that ACC is attributable to poorly controlled disease rather than thiourylenes. As yet the underlying mechanism is not understood, nor is it known why MMI and CMZ may cause potentially significant embryopathy while congenital defects attributable to the structurally similar propylthiouracil are typically less severe.

Innate Immunity in Autoimmune Thyroid Disease during Pregnancy

Autoimmune thyroid disease (AITD) is the most common organ-specific autoimmune disorder clinically presented as Hashimoto thyroiditis (HT) and Graves' disease (GD). The pathogenesis of AITD is caused by an inappropriate immune response related to genetic, non-genetic, and environmental factors. Pregnancy is one of the factors that have a great influence on the function of the thyroid gland because of the increased metabolic demand and the effects of hormones related to pregnancy. During pregnancy, an adaptation of the maternal immune system occurs, especially of the innate immune system engaged in maintaining adaptive immunity in the tolerant state, preventing the rejection of the fetus. Pregnancy-related hormonal changes (estrogen, progesterone, hCG) may modulate the activity of innate immune cells, potentially worsening the course of AITD during pregnancy. This especially applies to NK cells, which are associated with exacerbation of HD and GD. On the other hand, previous thyroid disorders can affect fertility and cause adverse outcomes of pregnancy, such as placental abruption, spontaneous abortion, and premature delivery. Additionally, it can cause fetal growth retardation and may contribute to impaired neuropsychological development of the fetus. Therefore, maintaining the thyroid equilibrium in women of reproductive age and in pregnant women is of the highest importance.

Therapeutic plasma exchange for Graves' disease in pregnancy

Graves' disease in pregnancy may be associated with maternal, fetal and neonatal complications, which are proportionate to the severity of hyperthyroidism. Optimal management is detailed preconception counselling, achievement of an euthyroid state prior to conception, and close monitoring of thyroid function and thyroid-stimulating antibodies together with judicious use of anti-thyroid medications during pregnancy. A case of Graves' disease in pregnancy, complicated by pancytopenia, with a deterioration in thyroid function following cessation of thionamide therapy is described here. Therapeutic plasma exchange was subsequently used to achieve rapid control prior to thyroidectomy. Therapeutic plasma exchange is an effective treatment for hyperthyroidism where thionamides are ineffective or contraindicated, as a bridge to definitive management.

Iodine and Thyroid Maternal and Fetal Metabolism during Pregnancy

Thyroid hormones and iodine are required to increase basal metabolic rate and to regulate protein synthesis, long bone growth and neuronal maturation. They are also essential for protein, fat and carbohydrate metabolism regulation. Imbalances in thyroid and iodine metabolism can negatively affect these vital functions. Pregnant women are at risk of hypo or hyperthyroidism, in relation to or regardless of their medical history, with potential dramatic outcomes. Fetal development highly relies on thyroid and iodine metabolism and can be compromised if they malfunction. As the interface between the fetus and the mother, the placenta plays a crucial role in thyroid and iodine metabolism during pregnancy. This narrative review aims to provide an update on current knowledge of thyroid and iodine metabolism in normal and pathological pregnancies. After a brief description of general thyroid and iodine metabolism, their main modifications during normal pregnancies and the placental molecular actors are described. We then discuss the most frequent pathologies to illustrate the upmost importance of iodine and thyroid for both the mother and the fetus.

Management of Hyperthyroidism during Pregnancy: A Systematic Literature Review

In pregnancy, several physiological changes affect maternal circulating thyroid hormone levels. The most common causes of hyperthyroidism in pregnancy are Graves' disease and hCG-mediated hyperthyroidism. Therefore, evaluating and managing thyroid dysfunction in women during pregnancy should ensure favorable maternal and fetal outcomes. Currently, there is no consensus regarding an optimal method to treat hyperthyroidism in pregnancy. The term "hyperthyroidism in pregnancy" was searched in the PubMed and Google Scholar databases to identify relevant articles published between 1 January 2010 and 31 December 2021. All of the resulting abstracts that met the inclusion period were evaluated. Antithyroid drugs are the main therapeutic form administered in pregnant women. Treatment initiation aims to achieve a subclinical hyperthyroidism state, and a multidisciplinary approach can facilitate this process. Other treatment options, such as radioactive iodine therapy, are contraindicated during pregnancy, and thyroidectomy should be limited to severe non-responsive thyroid dysfunction pregnant patients. In light of this events, even in the absence of guidelines certifying screening, it is recommended that all pregnant and childbearing women should be screened for thyroid conditions.

Optimizing Growth: The Case for Iodine

Iodine is an essential micronutrient and component of thyroid hormone. An adequate dietary iodine intake is critical to maintain and promote normal growth and development, especially during vulnerable life stages such as pregnancy and early infancy. The role of iodine in cognitive development is supported by numerous interventional and observational studies, and when iodine intake is too low, somatic growth is also impaired. This can be clearly seen in cases of untreated congenital hypothyroidism related to severe iodine deficiency, which is characterized, in part, by a short stature. Nevertheless, the impact of a less severe iodine deficiency on growth, whether in utero or postnatal, is unclear. Robust studies examining the relationship between iodine and growth are rarely feasible, including the aspect of examining the effect of a single micronutrient on a process that is reliant on multiple nutrients for optimal success. Conversely, excessive iodine intake can affect thyroid function and the secretion of optimal thyroid hormone levels; however, whether this affects growth has not been examined. This narrative review outlines the mechanisms by which iodine contributes to the growth process from conception onwards, supported by evidence from human studies. It emphasizes the need for adequate iodine public health policies and their robust monitoring and surveillance, to ensure coverage for all population groups, particularly those at life stages vulnerable for growth. Finally, it summarizes the other micronutrients important to consider alongside iodine when seeking to assess the impact of iodine on somatic growth.

Thyroid autoantibodies

Thyroid-stimulating hormone (TSH) receptor antibody (TSH-R-Ab or TRAb) testing plays a pivotal role in arriving at the aetiological diagnosis in patients with thyrotoxicosis. A positive test establishes the diagnosis of Graves' disease (GD) while a negative result in conjunction with imaging studies supports other possible aetiologies. In patients with GD, TRAb levels at diagnosis and at the time of withdrawal of antithyroid drugs can identify patients who are unlikely to achieve remission and guide clinical management decisions. We provide an algorithm that incorporates TRAb in the decision-making process for the management of thyrotoxicosis. The utility of TRAb in predicting the risk of fetal and neonatal thyroid dysfunction is established and widely accepted in guidelines. TRAb may also help in the diagnosis of Graves' orbitopathy, especially in euthyroid or hypothyroid patients and its role in guiding its management is evolving as a useful adjunct to the clinical parameters used in making therapeutic decisions.Anti-thyroid peroxidase antibodies (TPOAb) and anti-thyroglobulin antibodies (TgAb) indicate thyroid autoimmunity. The most common use of TPOAb is to identify patients at a higher risk of progression to treatment-requiring hypothyroidism. They also aid the diagnosis of immune thyroiditis and Hashimoto's encephalopathy. Thyroglobulin measurement is used to help guide differentiated thyroid cancer treatment. TgAb is used as an accompanying test with thyroglobulin measurement as its presence can interfere with the thyroglobulin assay. A negative TgAb result reduces the likelihood of, but does not exclude, interference with thyroglobulin assay.

Targeting neonatal Fc receptor: potential clinical applications in pregnancy

The neonatal Fc receptor (FcRn) plays an important role in the transfer of the immunoglobulin G isotype (IgG) from the mother to the fetus. FcRn expressed on endothelial cells also binds to IgG and albumin, regulating the circulating half-lives of these proteins. Alloimmune and autoimmune IgG antibodies have been implicated in various perinatal immune-mediated diseases. FcRn-mediated placental transfer of pathogenic antibodies can result in cell and tissue injury in the fetus and neonate, with devastating outcomes. Thus, blockade of FcRn may be an effective treatment strategy in managing these conditions and could additionally reduce the concentration of pathogenic antibodies in the maternal circulation by preventing IgG recycling. In this review, we discuss the biology of FcRn, the rationale and considerations for development of FcRn-blocking agents, and their potential clinical applications in various perinatal immune-mediated diseases. © 2022 International Society of Ultrasound in Obstetrics and Gynecology.

A prospective study among neonates born to mothers with active or past Graves disease

OBJECTIVE

The aim of this prospective study was to describe demographic and clinical characteristics of neonates born to mothers with active or past Graves disease and to assess compliance since implementation of a new protocol in our center.

METHODS

We prospectively followed up neonates born to mothers with active or past Graves disease in a tertiary hospital in Spain between August 2019 and September 2021 according to our protocol. We reviewed maternal and neonatal history of these neonates, and we followed up newborns at risk of neonatal hyperthyroidism.

RESULTS

Among 5808 births, 33 neonates were born to mothers with active or past Graves disease (0.57%). Six mothers (18.2%) had positive levels of thyroid-stimulating hormone receptor antibodies during pregnancy and five mothers (15.1%) between weeks 20 and 24 of pregnancy. Two of them had received definitive therapy for Graves disease before pregnancy. Two neonates (7.1%) were at high risk of neonatal hyperthyroidism and were followed-up until two months, without hyperthyroidism signs or abnormal thyroid hormone levels. Compliance of protocol during pregnancy was 84.9% and 75.8% at birth.

CONCLUSIONS

Prevalence of Graves disease among pregnant women was 0.57%, with no cases of neonatal hyperthyroidism. Compliance of protocol was adequate during pregnancy (84.9%) and acceptable at birth (75.8%).

Timing of Graves' Hyperthyroidism Management in Pregnant Women: Impact on the Infant Thyroid Volume

The thyroid of the fetus of a mother with Graves’ disease (GD) is affected by the transplacental passage of both antithyroid drugs (ATDs) and thyroid-stimulating hormone receptor antibodies (TRAb). Thyroid hormone imbalances are harmful for the developing brain. This study aimed to evaluate the impact of the duration of antithyroid drug treatment in hyperthyroid pregnant women with GD on infants’ thyroid volume. Twenty-nine neonates born to mothers with GD were divided into two groups depending on the duration of ATDs treatment. The ultrasound thyroid volumes of the infants were measured within the first week of life. Thyroid-stimulating hormone, thyroxine, and TRAb values were recorded. There was no difference between groups in the thyroid hormones’ values. The median thyroid volume for the entire group of neonates with mothers with GD, for the groups of neonates of mothers with long- and short-treated GD, and for the control group were 1.539, 1.816, 1.347 and 1.014 mL, respectively. There were statistically significant differences in the thyroid volume between the GD group and the control group, as well as between the groups of neonates of mothers with long- and short-treated GD (p < 0.05). Studies have shown that the longer the duration of ATDs administration to mothers, the greater the thyroid volume of the neonate.

Thyroid Storm Superimposed on Gestational Hypertension: A Case Report and Review of Literature

A thyroid storm is an extreme manifestation of thyrotoxicosis, and is life threatening without an early diagnosis. Pregnancy or childbirth may worsen maternal hyperthyroidism or induce the development of a thyroid storm. Gestational hypertension, a disorder defined as new-onset hypertension, develops after 20 weeks of gestation and shares symptoms with a thyroid storm. The diagnosis of a thyroid storm may be challenging in patients with gestational hypertension. To highlight the significance of early thyrotoxicosis-related gastrointestinal symptoms, we report a case of a 38-year-old woman with a twin pregnancy, who was diagnosed with gestational hypertension, and then developed a thyroid storm during the peripartum period. She complained of nausea and abdominal pain, followed by tachycardia, hypertension, and a disturbance of consciousness with desaturation. After emergency caesarean section, fever, diarrhea, and high-output heart failure, with pulmonary edema, were noted during the postoperative period in the intensive care unit. The diagnosis of a thyroid storm was confirmed using the Burch–Wartofsky point scale, which was 75 points. In this patient, the uncommon gastrointestinal symptoms, as initial manifestations of thyrotoxicosis, indicated the development of a thyroid storm. The distinguished presentation of thyrotoxicosis-induced cardiomyopathy and peripartum cardiomyopathy also helped in the differential diagnosis between a thyroid storm and gestational hypertension. Aggressive treatment for thyrotoxicosis should not be delayed because of a missed diagnosis.

How to manage Graves' disease in women of childbearing potential

The management of Graves' disease (GD) in women of childbearing potential has multiple specific complexities. Many factors are involved, which differ at the various stages from preconception, conception, first trimester, later pregnancy, postpartum and lactation, with both maternal and foetal considerations. The incidence and significance of the risks incurred from antithyroid drugs (ATDs) in pregnancy have been re-evaluated recently and must be balanced against the risks of uncontrolled hyperthyroidism during childbearing years. Contraception is advised until hyperthyroidism is controlled. ATD cessation should be considered in those who are well controlled on low dose therapy before conception and in early pregnancy. Advice on iodine supplementation does not generally differ in those with GD. Radioiodine (RAI) is contraindicated from 6 months preconception until completion of breastfeeding. In all women who have a history of GD, monitoring of TSH receptor antibodies (TRAb) is strongly recommended during pregnancy, and if elevated, foetal monitoring and assessment of thyroid function in the neonate are required. Of note, RAI increases TRAb for up to a year, making this treatment option even less attractive in this patient group. A small amount of ATD is transferred into breast milk but low doses are safe during lactation. Routine periodic thyroid function testing is recommended in remission to detect postpartum GD recurrence. We present our approach to the Clinical Question 'How to manage GD in women of childbearing potential?'

Relationship between thyroid hormone parameters and exposure to a mixture of organochlorine pesticides, mercury and nutrients in the cord blood of newborns

The fetus is prenatally exposed to a mixture of organochlorine pesticides (OCPs), mercury (Hg), docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA) and selenium (Se) through maternal seafood consumption in real-life scenario. Prenatal exposure to these contaminants and nutrients has been suggested to affect thyroid hormone (TH) status in newborns, but the potential relationships between them are unclear and the joint effects of the mixture are seldom analyzed. The aim of the study is to investigate the associations of prenatal exposure to a mixture of OCPs, Hg, DHA, EPA and Se with TH parameters in newborns. 228 mother-infant pairs in Shanghai, China were included. We measured 20 OCPs, total Hg, DHA, EPA and Se in cord blood samples as exposure variables. The total thyroxine (TT4), free thyroxine (FT4), total triiodothyronine (TT3), free triiodothyronine (FT3), and thyroid-stimulating hormone (TSH) levels and the FT3/FT4 ratio in cord serum were determined as outcomes. Using linear regression models, generalized additive models and Bayesian kernel machine regression, we found dose-response relationships of the mixture component with outcomes: among the contaminants, p,p'-DDE was the most important positive predictor of TT3, while HCB was predominantly positively associated with FT3 and the FT3/FT4 ratio, indicating different mechanisms underlying these relationships; among the nutrients, EPA was first found to be positively related to the FT3/FT4 ratio. Additionally, we found suggestive evidence of interactions between p,p'-DDE and HCB on both TT3 and FT3, and EPA by HCB interactions for TT3, FT3 and FT3/FT4 ratio. However, the overall effects of the mixture on thyroid hormone parameters were not significant. Our result suggests that prenatal exposure to p,p'-DDE, HCB and EPA as part of a mixture might affect thyroid function of newborns in independent and interactive ways. The potential biological mechanisms merit further investigation.

Maternal thyroid function in multiple pregnancies - a systematic review

BACKGROUND

The function of the thyroid gland during pregnancy undergoes physiological changes to ensure the proper amount of thyroid hormones for both the pregnant woman and the fetus. Multiple pregnancies (MP) are characterized by specific differences compared to single pregnancies, e.g., higher concentrations of human chorionic gonadotropin, which also affect thyroid function. The aim was to collect available knowledge on maternal thyroid function in MP.

METHODS

We have systematically searched three databases: the PubMed/MEDLINE, Scopus and the Cochrane Library. The last search was run on the 4th of August 2022. We included full-text original observational and experimental studies written in English. Case reports, editorials, letters, conference abstracts, reviews and meta-analyses were excluded. No time criterion was established. Studies were considered eligible if at least one maternal thyroid function test was performed and reported. Studies on MP with a co-existing mole were excluded. The risk of bias was assessed with the use of the AXIS tool. The qualitative synthesis of evidence was applied.

RESULTS

The search strategy resulted in the identification of 821 manuscripts. After removing duplicates, we screened the titles and abstracts of 552 articles, out of which 57 were selected for full-text analysis. Finally, 12 articles were included in the review. They were conducted in 6 different countries and published between the years 1997 and 2022. The number of examined women with MP ranged from 9 to 1 626.

DISCUSSION AND CONCLUSIONS

Thyroid function differs between women with MP and SP. Scarce data are available on the topic, but MPs are most likely characterized by higher HCG levels, which influences thyroid-stimulating hormone and free thyroid hormone levels. These differences are mainly expressed in the 1st trimester of pregnancy. Separate population-based reference ranges are needed to correctly diagnose thyroid diseases in MP and to avoid unnecessary treatment. Further research is needed to fill the knowledge gaps.

Changes in Thyrotropin Receptor Antibody Levels Following Total Thyroidectomy or Radioiodine Therapy in Patients with Refractory Graves' Disease

Background: The actions of thyrotropin-binding inhibitory immunoglobulins (TBIIs) against thyrotropin receptors in thyroid follicular cells have been studied as important etiological factors in Graves' disease (GD). The purpose of this study was to investigate changes in the TBII levels of patients undergoing total thyroidectomy (TTx) or radioactive iodine (RAI) therapy for GD refractory to antithyroid drugs (ATDs). Methods: We enrolled patients who underwent TTx or RAI for GD with previous ATD use between January 2011 and December 2017 at the Samsung Medical Center in Seoul, Korea. Thorough retrospective reviews of medical records were performed in 130 patients. Results: Patients with goiter, ophthalmopathy, high levels of TBIIs, and high doses of ATDs received TTx. Elderly patients with arrhythmia received RAI. We observed that TBII levels continued to decrease after TTx. On the contrary, TBIIs initially increased for 138 days (estimated median time) and then decreased slowly after RAI. A faster decline in TBII levels was observed in the TTx group than in the RAI group (p < 0.001). The estimated median time for TBIIs to decrease below 4.5 IU (3 × upper normal limit, which is known to be a risk factor for fetal hyperthyroidism) was 318 days in the TTx group and 659 days in the RAI group, respectively. In the RAI group, high levels of TBII (>4.5 IU/L) were present in 70 (82%) at 6 months, 57 (67%) at 1 year, and 3 (3%) at 2 years. In the TTx group, rapid decreases in TBII levels were observed in younger patients and those with lower baseline TBII levels. In the RAI group, smaller thyroid volume was correlated with more rapid decrease in TBII levels. Conclusions: The changes in TBII levels following TTx or RAI were different in patients with refractory GD. When deciding on TTx or RAI, this difference should be considered with patient age, severity of hyperthyroidism, goiter, ophthalmopathy, and future pregnancy plans (for young female patients).

Characteristics of pregnant women with diabetes using injectable glucose-lowering drugs in the EVOLVE study

AIMS

To examine clinical parameters, glycemic control, folic acid supplementation, and the presence of other chronic diseases during early pregnancy in the EVOLVE study population (women with pre-existing diabetes treated with injectable glucose-lowering drugs).

METHODS

Cross-sectional baseline evaluation of EVOLVE: an international, multicenter, non-interventional study investigating the safety of injectable glucose-lowering drugs in pregnant women with pre-existing type 1 (T1D) or type 2 diabetes (T2D). Data were collected at enrollment visit interviews before gestational week 16.

RESULTS

In total, 2383 women from 17 mainly European countries were enrolled in the study: 2122 with T1D and 261 with T2D; mean age was 31 and 33 years, and duration of diabetes was 15 and 6 years, respectively. For women with T1D or T2D, 63% and 75%, respectively, received basal and rapid-acting insulin, 36% and 3% rapid-acting insulin only, 0.7% and 14.0% basal insulin only, 0.2% and 5.4% premix insulin, 0.0% and 1.2% injectable glucagon-like peptide-1 receptor agonist treatment without insulin. In women with T1D or T2D, respectively, during early pregnancy, 59% and 62% had HbA_1c <7.0% (53 mmol/mol); 16% and 36% reported not taking folic acid before or during early pregnancy. Overall, >40% of women had ≥1 chronic concomitant condition (predominantly thyroid disease or hypertension). Retinopathy was the most commonly reported diabetic complication. The most commonly reported previous pregnancy complication was miscarriage.

CONCLUSIONS

Baseline data from this large multinational population of women with pre-existing diabetes indicate that sub-optimal glycemic control, poor pregnancy planning, and chronic concomitant conditions were common in early pregnancy.

Pregnancy in catecholaminergic polymorphic ventricular tachycardia: therapeutic optimization and multidisciplinary care are key to success

Women of child-bearing age comprise a large proportion of the patients followed by inherited arrhythmia clinics. Despite being a rare and dangerous diagnosis, cardiac and obstetric care providers should know that catecholaminergic polymorphic ventricular tachycardia (CPVT) is not a contraindication to pregnancy. In fact, pregnancy was not associated with an increased risk of CPVT-associated arrhythmias in a recent large cohort study, and most guideline-based anti-arrhythmic drug treatments are life-saving and carry a low risk of teratogenesis. In principle, the potential for CPVT destabilization may be more likely to occur after anti-arrhythmic drugs are decreased or stopped during pregnancy, when an implantable cardioverter defibrillator (ICD) shock exacerbates catecholamine release, or if adrenaline surges are triggered by labor and delivery. Therefore, all pregnant women should be followed by a cardio-obstetrics team with extensive knowledge of CPVT diagnosis, as well as arrhythmia risk stratification fand management. This multidisciplinary care should begin preconception and involve counseling on preimplantation genetic testing, choosing safe and effective anti-arrhythmic drugs, stopping contraindicated medications, optimal programming of ICDs, and planning for the brief hyper-adrenergic period of labor and delivery. The latest data on pregnancy in CPVT is reviewed here and the optimal care for this rare and complex patient population outlined.

Maternal hyperthyroidism and pregnancy outcomes: A population-based cohort study

OBJECTIVE

Maternal hyperthyroidism and antithyroid medications have been associated with adverse pregnancy and perinatal outcomes. This nationwide register-based study investigated the association of maternal hyperthyroidism and antithyroid drug (ATD) use with pregnancy outcomes and included all singleton births in Finland between 2004 and 2013 (N = 571 785).

DESIGN, PATIENTS AND MEASUREMENTS

Hyperthyroid mothers were identified in the Medical Birth Register, and data on ATD use before and/or during pregnancy were collected from the Prescription Register. The odds ratios, with 95% confidence intervals, for adverse outcomes among hyperthyroid mothers and mothers without thyroid disease were compared using logistic regression.

RESULTS

In total, 2144 (0.37%) of all the women had diagnoses of hyperthyroidism, and 580 (27%) of these women had used ATDs before and/or during pregnancy. Compared to the mothers without thyroid disease, maternal hyperthyroidism was associated with older age, multiparity, smoking, previous miscarriages, and overweight or obesity. The mothers diagnosed with hyperthyroidism also had increased odds of gestational hypertensive disorders, caesarean sections, placental abruptions, preterm births, small-for-gestational-age newborns and neonatal intensive care unit treatment. The odds of pregnancy and/or perinatal complications were higher among those who had used ATDs (indicative of active disease), but those who had not received ATD treatment also had increased odds of such complications compared to the mothers without thyroid disease.

CONCLUSIONS

Women with active hyperthyroidism and those with histories of hyperthyroidism should be considered at risk of developing pregnancy and perinatal complications and should therefore be monitored during pregnancy.

Thyroid disorders in subfertility and early 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.

Management of neonates born to mothers with thyroid dysfunction, and points for attention during pregnancy

Thyroid hormone (TH) is indispensable for normal embryonic and fetal development. Throughout gestation TH is provided by the mother via the placenta, later in pregnancy the fetal thyroid gland makes an increasing contribution. Maternal thyroid dysfunction, resulting in lower or higher than normal (maternal) TH levels and transfer to the embryo/fetus, can disturb normal early development. (Maternal) thyroid dysfunction is mostly caused by autoimmune hypo- or hyperthyroidism, i.e. Hashimoto and Graves disease. Autoimmune hyperthyroidism is caused by stimulating TSH receptor antibodies (TSHR Ab), patients with autoimmune hypothyroidism may have blocking TSHR Ab. Maternal TSHR Ab cross the placenta from mid gestation and may cause fetal and transient neonatal hyper- or hypothyroidism. Anti-thyroid drugs taken for autoimmune hyperthyroidism cross the placenta throughout gestation, and may cause fetal and transient neonatal hypothyroidism. This review focusses on the consequences of maternal hypo- and hyperthyroidism for fetus and neonate, and provides a practical approach to clinical management of neonates born to mothers with thyroid dysfunction.

The role of beliefs about the impact of illness on fertility and close relationships for psychopathological symptoms in women treated for hypothyroidism

OBJECTIVE

As demonstrated in a pilot study, hypothyroidism has a highly stressful impact on some areas of functioning. This study aims to evaluate the connection between illness-related beliefs (IRBs) and the impact of hypothyroidism on fertility and close relationships, which were the strongest stressors, and the level of depressive, anxiety, and anger symptoms.

METHODS

Two hundred and thirteen women being treated for hypothyroidism took part in an online survey and completed the modified Hospital Anxiety and Depression Scale, Hypothyroidism Symptoms Severity rating scales, and a measure of IRBs. Other relevant clinical data were also collected.

RESULT

Mean levels of thyroid-stimulating hormone indicated that the women were euthyroid. Four groups of participants were identified based on IRBs. The group holding a strong IRB about the negative impact of illness only on close relationships scored significantly higher on depressive symptoms than women in the other groups. The group holding strong IRBs about the negative impact of illness on both close relationships and fertility scored significantly higher on anxiety symptoms than the women in the other groups. Regression analysis showed that IRBs about the negative impact of hypothyroidism predicted anxiety, depressive, and anger symptoms.

CONCLUSIONS

Negative IRBs about the impact of illness on fertility and close relationships contribute to increased levels of emotional distress symptoms in women being treated for hypothyroidism.

Hyperthyroidism During Pregnancy: A Clinical Approach

Hyperthyroidism is relatively uncommon during pregnancy. However, those caring for pregnant patients should be versed in the evaluation and management of hyperthyroidism, as there are potential maternal and fetal implications that are related to the disease and to treatment. The differential diagnosis of hyperthyroidism includes clinical and subclinical entities, as well as transient laboratory findings that are related to the pregnancy itself. The clinical management, including the indications for the use of thioamide or antithyroid medications, will be discussed in the context of pregnancy. Finally, considerations for the management of the postpartum and/or breastfeeding patient with hyperthyroidism will be reviewed.

Neonatal Thyroid Function and Disorders

Thyroid hormone is essential for normal fetal brain development in utero and for the first 2 years of life. The developing fetus is initially reliant upon maternal thyroid hormones that cross the placenta, until the fetal thyroid begins to supply thyroid hormone for the fetus. Maternal thyroid status affects fetal thyroid function and maternal thyroid dysfunction can have a significant impact on the fetus and neonate. There are also several neonatal factors that can influence thyroid function. Here, we describe thyroid function in the fetus and neonate and discuss the most common thyroid disorders seen in neonates.

Postpartum Thyroid Storm in Poorly Controlled Graves' Disease: A Case Report

Hyperthyroidism during pregnancy is a relatively rare event, but poor control of hyperthyroidism during pregnancy is associated with a host of issues. These include intrauterine fetal demise, hypertensive disorders of pregnancy, preterm delivery, low birth weight, intrauterine growth restriction, and maternal congestive heart failure. One of the most feared sequelae of hyperthyroidism is thyroid storm, which has a mortality rate >10%. Patients who develop thyroid storm present several challenges to anesthesiologists including hemodynamic instability and medication management. Here, we present the anesthetic management for a parturient whose delivery was complicated by signs and symptoms consistent with thyroid storm.

Maternal selenium deficiency during pregnancy in mice increases thyroid hormone concentrations, alters placental function and reduces fetal growth

KEY POINTS

Inappropriate intake of key micronutrients in pregnancy is known to alter maternal endocrine status, impair placental development and induce fetal growth restriction. Selenium is an essential micronutrient required for the function of approximately 25 important proteins. However, the specific effects of selenium deficiency during pregnancy on maternal, placental and fetal outcomes are poorly understood. The present study demonstrates that maternal selenium deficiency increases maternal triiodothyronine and tetraiodothyronine concentrations, reduces fetal blood glucose concentrations, and induces fetal growth restriction. Placental expression of key selenium-dependent thyroid hormone converting enzymes were reduced, whereas the expression of key placental nutrient transporters was dysregulated. Selenium deficiency had minimal impact on selenium-dependent anti-oxidants but increased placental copper concentrations and expression of superoxide dismutase 1. These results highlight the idea that selenium deficiency during pregnancy may contribute to thyroid dysfunction, causing reduced fetal growth, that may precede programmed disease outcomes in offspring.

ABSTRACT

Selenium is a trace element fundamental to diverse homeostatic processes, including anti-oxidant regulation and thyroid hormone metabolism. Selenium deficiency in pregnancy is common and increases the risk of pregnancy complications including fetal growth restriction. Although altered placental formation may contribute to these poor outcomes, the mechanism by which selenium deficiency contributes to complications in pregnancy is poorly understood. Female C57BL/6 mice were randomly allocated to control (>190 µg kg-1 , n = 8) or low selenium (<50 µg kg-1 , n = 8) diets 4 weeks prior to mating and throughout gestation. Pregnant mice were killed at embryonic day 18.5 followed by collection of maternal and fetal tissue. Maternal and fetal plasma thyroid hormone concentrations were analysed, as was placental expression of key selenoproteins involved in thyroid metabolism and anti-oxidant defences. Selenium deficiency increased plasma tetraiodothyronine and triiodothyronine concentrations. This was associated with a reduction in placental expression of key selenodependent deiodinases, DIO2 and DIO3. Placental expression of selenium-dependent anti-oxidants was unaffected by selenium deficiency. Selenium deficiency reduced fetal glucose concentrations, leading to reduced fetal weight. Placental glycogen content was increased within the placenta, as was Slc2a3 mRNA expression. This is the first study to demonstrate that selenium deficiency may reduce fetal weight through increased maternal thyroid hormone concentrations, impaired placental thyroid hormone metabolism and dysregulated placental nutrient transporter expression. The study suggests that the magnitude of selenium deficiency commonly reported in pregnant women may be sufficient to impair thyroid metabolism but not placental anti-oxidant concentrations.

Hyperthyroid heart disease in pregnancy: Retrospective analysis of a case series and review of the literature

BACKGROUND

Hyperthyroidism in pregnancy may pose a great threat to maternal and fetal health. The risk of hyperthyroid heart disease (HHD), even heart failure, is significantly elevated in pregnant women.

AIM

To investigate the clinical characteristics, prognosis, and therapy of HHD in pregnant women.

METHODS

We searched the patient registry data at West China Second University Hospital of Sichuan University in Chengdu, China, following the approval by the Ethics Committee. We retrospectively analyzed the clinical characteristics of pregnant women diagnosed with HHD. The medical records of women with HHD during pregnancy from January 2012 to December 2017 were obtained from the electronic medical records system. All the included patients were followed in outpatient clinics and by telephone interviews until October 2018.

RESULTS

A total of 155 patients were diagnosed with thyrotoxicosis, of whom six were diagnosed with HHD. Three of them had regular antenatal care. Two patients were complicated with acute heart failure attacks, and one of them had a stillbirth. Both of these patients had a long history of Graves’ disease with poor treatment compliance. Treatments of precipitating factors such as the control of infection could relieve the symptoms and prolong gestation for a better prognosis. Hyperthyroid heart failure could be controlled with aggressive diuretics and management of the coexisting complications. Intense monitoring and timely anti-heart failure treatment were crucial in patients with severe cardiac damage. Our findings indicated the importance of regular antenatal care and treatment adherence in patients with hyperthyroidism.

CONCLUSION

The timely and accurate diagnosis of HHD and the implementation of effective management are important for a better prognosis in pregnant women with HHD. Improvement in patients’ awareness of thyrotoxicosis is needed.

Graves' hyperthyroidism in pregnancy

PURPOSE OF REVIEW

Graves' hyperthyroidism is associated with significant obstetric, maternal, fetal, and neonatal complications. Early diagnosis and an understanding of the management of Graves' hyperthyroidism in pregnancy can help to prevent these complications. Antithyroid drugs (ATD) should be avoided in early pregnancy, given their association with congenital malformations.

RECENT FINDINGS

TSH-receptor antibodies (TRAb) are integral in the management of Graves' hyperthyroidism in pregnancy and in the preconception period. TRAb are indicative of the current activity of Graves' hyperthyroidism and the likelihood of relapse. Furthermore, TRAb predicts the risk of fetal and neonatal hyperthyroidism.The incidence of congenital malformations is roughly the same for propylthiouracil (PTU) and methimazole (MMZ). Exposure to both ATDs in early pregnancy has been associated with increased incidence of congenital malformations compared with exposure to either ATD alone.

SUMMARY

The goal of the physician is maintaining euthyroidism throughout pregnancy and delivery of a healthy, euthyroid baby. An understanding of the natural progression of Graves' hyperthyroidism in pregnancy and the proper utilization of TRAb enables the physician to minimize the risks associated with Graves' hyperthyroidism and side effects of ATDs unique to pregnancy. The physician should prioritize preconception counseling in women with Graves' hyperthyroidism in order to avoid hyperthyroidism and having to use ATDs in pregnancy.

Graves' disease complicated by fetal goitrous hypothyroidism treated with intra-amniotic administration of levothyroxine

Fetal goitrous hypothyroidism is a rare entity and is caused mainly by maternal treatment of Graves' disease (GD). We report a case of a 22-year-old woman referred at 12 weeks of gestation due to hyperthyroidism subsequent to recently diagnosed GD. She started treatment with propylthiouracil and, at 21 weeks of gestation, fetal goitre was detected. A cordocentesis confirmed the diagnosis of fetal goitrous hypothyroidism, and intra-amniotic administration of levothyroxine (LT4) was performed and repeated through the pregnancy due to maintenance of fetal goitre. The pregnancy proceeded without further complications and a healthy female infant was born at 37 weeks of gestation, with visible goitre and thyroid function within the normal range at birth. Although there is no consensus on the optimal dose, the number of injections and the interval between them, intra-amniotic LT4 administration is recommended once fetal goitrous hypothyroidism is suspected, in order to prevent long-term complications of fetal hypothyroidism.

Thyroid function and thyroid disorders during pregnancy: a review and care pathway

PURPOSE

To review the literature on thyroid function and thyroid disorders during pregnancy.

METHODS

A detailed literature research on MEDLINE, Cochrane library, EMBASE, NLH, ClinicalTrials.gov, and Google Scholar databases was done up to January 2018 with restriction to English language about articles regarding thyroid diseases and pregnancy.

RESULTS

Thyroid hormone deficiencies are known to be detrimental for the development of the fetus. In particular, the function of the central nervous system might be impaired, causing low intelligence quotient, and mental retardation. Overt and subclinical dysfunctions of the thyroid disease should be treated appropriately in pregnancy, aiming to maintain euthyroidism. Thyroxine (T4) replacement therapy should reduce thyrotropin (TSH) concentration to the recently suggested fixed upper limits of 2.5 mU/l (first and second trimester) and 3.0 mU/l (third trimester). Overt hyperthyroidism during pregnancy is relatively uncommon but needs prompt treatment due to the increased risk of preterm delivery, congenital malformations, and fetal death. The use of antithyroid drug (methimazole, propylthiouracil, carbimazole) is the first choice for treating overt hyperthyroidism, although they are not free of side effects. Subclinical hyperthyroidism tends to be asymptomatic and no pharmacological treatment is usually needed. Gestational transient hyperthyroidism is a self-limited non-autoimmune form of hyperthyroidism with negative antibody against TSH receptors, that is related to hCG-induced thyroid hormone secretion. The vast majority of these patients does not require antithyroid therapy, although administration of low doses of β-blocker may by useful in very symptomatic patients.

CONCLUSIONS

Normal maternal thyroid function is essential in pregnancy to avoid adverse maternal and fetal outcomes.

Resistant Thyrotoxicosis due to Graves' Disease in Pregnancy: Case Report and Review of the Literature

The effective management of Graves' disease (GD) during pregnancy is crucial for maternal and neonatal well-being. Conventional treatment of GD during pregnancy includes antithyroid drugs (ATDs) and surgery, ideally during the second trimester. We report a 27-year-old woman with GD and we present the course of GD during her three consecutive pregnancies. During the first pregnancy, thyrotoxicosis was successfully treated with low doses of antithyroid drugs; in the second pregnancy, thyrotoxicosis was only controlled at the third trimester; while in the third pregnancy, our patient presented with treatment-resistant thyrotoxicosis, which was finally managed with corticosteroids in adjunction with ATDs. Although hyperthyroid, the patient maintained her fertility. Resistance to ATD is a rare condition and in our case was adequately controlled with corticosteroids.