Management of Graves' hyperthyroidism in pregnancy: focus on both maternal and foetal thyroid function, and caution against surgical thyroidectomy in pregnancy

Preconceptional Counseling in Women with Hyperthyroidism

Preconception evaluation of couples wishing to conceive is an important step toward a healthy pregnancy and it is especially important in people with a chronic condition or at genetic risk. The most common endocrine disorders in women at reproductive age are those involving the thyroid gland and it is well recognized that hyperthyroidism (HT), over-function of the thyroid gland, is associated with risks of maternal, fetal, and neonatal complications. The aim of this paper is to review the latest evidence regarding the components of preconception counseling in women with HT that contemplate a pregnancy. We also want to raise awareness among healthcare professionals about the importance of periconceptional counseling in improving pregnancy outcomes and avoid maternal and fetal complications related to thyroid dysfunction. In women with Graves' disease seeking pregnancy, it is essential to discuss all the treatment options along with the associated risks and benefits. Extensive prospective studies are still needed to understand the implications of current recommended strategies for the management of HT in preconception and during pregnancy.

Management of foetal hyperthyroidism in a mother with autoimmune hypothyroidism: A case report

Foetal hyperthyroidism is mediated by transplacental passage of thyroid stimulating antibodies (TSAbs) and affects mothers with autoimmune (AI) thyroid disease. We report a case of a 33-year-old woman with a history of AI hypothyroidism and raised TSI after 2 stillbirths with suspect foetal hyperthyroidism. At 20.5 gestational weeks (GW) of her third pregnancy, foetal tachycardia and goitre were detected. TSI levels were 30.9mUI/mL. Methimazole (MMI) was started and adjusted based on ultrasound signs (foetal heart rate and thyroid gland vascularisation). The neonate was born at 35GW and cord blood revealed decreased TSH and normal free T4. MMI was started in the neonate at 2 days of life due to the appearance of asymptomatic hyperthyroidism. This case illustrates a rare recurrence of foetal hyperthyroidism in a mother with AI hypothyroidism. Pregestational thyroidectomy, TSAbs determination, early ultrasound diagnosis and foetal therapy helped us to improve obstetric outcomes.

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.

Recommendations of the AGG (Working Group for Obstetrics, Department of Maternal Diseases) on How to Treat Thyroid Function Disorders in Pregnancy

Objective These recommendations from the AGG (Committee for Obstetrics, Department of Maternal Diseases) on how to treat thyroid function disorder during pregnancy aim to improve the diagnosis and management of thyroid anomalies during pregnancy.

Methods Based on the current literature, the task force members have developed the following recommendations and statements. These recommendations were adopted after a consensus by the members of the working group.

Recommendations The following manuscript gives an insight into physiological and pathophysiological thyroid changes during pregnancy, recommendations for clinical and subclinical hypo- and hyperthyroidism, as well as fetal and neonatal diagnostic and management strategies.

Incidence of and Risk Factors for Neonatal Hypothyroidism Among Women with Graves' Disease Treated with Antithyroid Drugs Until Delivery

Background: The incidence of neonatal hypothyroidism among newborns born to mothers with Graves' disease (GD) who continued antithyroid drug (ATD) treatment until delivery has never been reported. Objective: Our primary objective was to investigate the incidence of neonatal hypothyroidism among newborns born to mothers with GD who were treated with ATD until delivery. Our secondary objective was to identify the cutoff ATD daily doses for neonatal hypothyroidism risk, based on maternal thyrotropin (TSH) receptor antibody (TRAb) levels. Methods: We conducted a retrospective cohort study. We included 305 pregnant women with GD who were treated with an ATD until delivery (63 treated with methimazole [MMI] and 242 treated with propylthiouracil [PTU]). Umbilical cord TSH, free thyroxine (fT4), and TRAb levels were measured at delivery, and we investigated the respective relationships between neonatal hypothyroidism at delivery and maternal fT4 levels, TRAb levels, and daily ATD doses during pregnancy. Neonatal hypothyroidism was diagnosed when the umbilical cord fT4 level was below the lower limit of the reference range. Results: The incidence of neonatal hypothyroidism at delivery was 19.0% ([confidence interval, CI, 11.2-30.4]; 12/63) in the MMI group and 12.8% ([CI, 9.2-17.6]; 31/242) in the PTU group. Neonatal goiter was observed in one neonate in the PTU group, and two infants in the PTU group required levothyroxine treatment. The daily ATD dose in the third trimester was the strongest predictor of neonatal hypothyroidism at delivery; the cutoff MMI dose was 10 mg/day, and the cutoff PTU dose was 150 mg/day. When the maternal TRAb level in the third trimester was above three times the upper limit of the normal range, the cutoff MMI dose was 20 mg/day, and the cutoff PTU dose was 150 mg/day. Conclusions: Maternal fT4 and TRAb levels were higher in the neonatal hypothyroid group, which suggested prolonged GD activity. Careful follow-up is necessary when maternal GD remains active and the ATD dose to control maternal thyrotoxicosis cannot be reduced.

Preconceptional thyroid stimulating hormone level and fecundity: a community-based cohort study of time to pregnancy

OBJECTIVE

To investigate the association between preconception thyroid stimulating hormone (TSH) level and time to pregnancy within a community-based population.

DESIGN

A community-based cohort study.

SETTING

Two free preconception check-up centers.

PATIENT(S)

Women who enrolled in the National Free Preconception Check-up Projects from January 1, 2018 to December 31, 2018 in Tianhe and Zengcheng districts of Guangzhou city.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Time to pregnancy.

RESULT(S)

A total of 1,478 women were eligible for the analysis; of these, 1,401 had a preconception TSH level within the range of 0.50 and 5.59 mIU/L (2.5th-97.5th percentiles) were taken as target study population. Among them, 968 (69.1%) couples achieved pregnancy within the first 6 months and 1,082 (77.2%) within 12 months. Dichotomized by the recommended cut-off value of 2.5 mIU/L, the percentage of women conceived in the high TSH level category (2.50-5.59 mIU/L) was comparable to that of the low category (0.50-2.49 mIU/L) (79.0% vs. 78.1%), with a crude fecundity odd ratio of 0.99 (95% confidence interval at 0.87-1.13). No statistically significant difference was observed after the adjustment in all models. Continuous TSH level was further examined, and the nonlinear association between TSH level and fecundity odds ratios was of no statistical significance.

CONCLUSION(S)

Preconception TSH level was not associated with fecundity in a healthy community-based population. Women attempting pregnancy with a TSH level ≥ 2.5 mIU/L can be reassured that they are unlikely to have an increased time to pregnancy.

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.

Diagnosis and Management of Fetal and Neonatal Thyrotoxicosis

Background and Objectives: Clinical fetal thyrotoxicosis is a rare disorder occurring in 1-5% of pregnancies with Graves' disease. Although transplacental passage of maternal TSH receptor stimulating autoantibodies (TRAb) to the fetus occurs early in gestation, their concentration in the fetus is reduced until the late second trimester, and reaches maternal levels in the last period of pregnancy. The mortality of fetal thyrotoxicosis is 12-20%, mainly due to heart failure. Case report: We present a case of fetal and neonatal thyrotoxicosis with favorable evolution under proper treatment in a 37-year-old woman. From her surgical history, we noted a thyroidectomy performed 12 years ago for Graves' disease with orbitopathy and ophthalmopathy; the patient was hormonally balanced under substitution treatment for post-surgical hypothyroidism and hypoparathyroidism. From her obstetrical history, we remarked a untreated pregnancy complicated with fetal anasarca, premature birth, and neonatal death. The current pregnancy began with maternal euthyroid status and persistently increased TRAb, the value of which reached 101 IU/L at 20 weeks gestational age and decreased rapidly within 1 month to 7.5 IU/L, probably due to the placental passage, and occurred simultaneously with the development of fetal tachycardia, without any other fetal thyrotoxicosis signs. In order to treat fetal thyrotoxicosis, the patient was administered methimazole, in addition to her routine substitution of 137.5 ug L-Thyroxine daily, with good control of thyroid function in both mother and fetus. Conclusions: Monitoring for fetal thyrotoxicosis signs and maternal TRAb concentration may successfully guide the course of a pregnancy associated with Graves' disease. An experienced team should be involved in the management.

Associations between hyperthyroidism and adverse obstetric and neonatal outcomes: A study of a population database including almost 17,000 women with hyperthyroidism

OBJECTIVE

Large population-based studies on maternal hyperthyroidism's effect on antepartum, intrapartum, and neonatal complications are few. Most of these studies were small or did not evaluate a broad scope of possible complications. Therefore, a large population-based cohort study was conducted to study the associations between maternal hyperthyroidism and pregnancy and perinatal complications.

DESIGN

This is a retrospective population-based cohort study utilizing data from the Healthcare Cost and Utilization Project-Nationwide Inpatient Sample over 11 years from 2004 to 2014.

PATIENTS

16,984 deliveries to women with hyperthyroidism and 9,079,804 deliveries to mothers who did not suffer of hyperthyroidism.

METHODS

A cohort of all deliveries between 2004 and 2014 inclusively was created. Within this group, all deliveries to women with hyperthyroidism were the study group (n = 16,984) and the remaining deliveries were categorized as nonhyperthyroidism births and comprised the reference group (n = 9,079,804). The main outcome measures were pregnancy and perinatal complications.

RESULTS

Maternal hyperthyroidism was associated with several pregnancy and perinatal complications, including increased risks of gestational hypertension (adjusted odds ratio [aOR]: 1.236, 95% confidence interval [CI]: 1.045-1.462, p = .013) and preeclampsia (aOR: 1.190, 95% CI: 1.006-1.408, p = .042). These patients are more likely to experience preterm premature rupture of membranes (aOR: 1.322, 95% CI: 1.007-1.735, p = .044), preterm delivery (aOR: 1.287 95% CI: 1.132-1.465, p < .001), placental previa (aOR: 1.527, 95% CI: 1.082-2.155, p = .016), and suffer from venous thromboembolism (aOR: 2.894, 95% CI: 1.293-6.475, p = .010). As for neonatal outcomes, small for gestational age and stillbirth were more likely to occur in the offspring of women with hyperthyroidism (aOR: 1.688, 95% CI: 1.437-1.984, p < .001 and aOR: 1.647, 95% CI: 1.109-2.447, p = .013, respectively).

CONCLUSIONS

Women with hyperthyroidism are more likely to experience pregnancy, delivery, and neonatal complications. We found an association between hyperthyroidism and hypertensive disorders, preterm delivery, and intrauterine fetal death.

Preconception Counseling and Care for Pregnant Women with Thyroid Disease

Thyroid disease is associated with adverse maternal and fetal outcomes. Appropriate reference ranges should be used for the interpretation of test results, although universal screening for thyroid dysfunction is not warranted. Overt thyroid dysfunction requires careful consideration of medication adjustments and close monitoring. Mild thyroid hypofunction has been linked to adverse pregnancy outcomes including preterm delivery, and poor neurocognition in the offspring. This review summarizes the most recent evidence on the counseling and management of women with thyroid disease before and during pregnancy and highlights the areas of controversy in need of further research.

Gastroschisis Due to Maternal Exposure to Carbimazole in A Term Neonate

Pregnant women with hyperthyroidism need careful management, which is due to the increased risk of maternal and fetal complications. However, safe and effective therapies for hyperthyroidism during pregnancy remain limited. Carbimazole is an anti-thyroid agent and has been used to treat hyperthyroidism. Gastroschisis is a congenital severe abdominal birth defect of the fetus but its etiology remains unclear. Here, we present a case of a female term neonate who developed gastroschisis after being exposed to carbimazole in uteroduring the first and half of the second trimester.

TSH-receptor autoantibodies in patients with chronic thyroiditis and hypothyroidism

OBJECTIVES

The reported prevalence of TSH-receptor (TSHR) autoantibodies (TRAb) in patients with chronic thyroiditis (CT) range from 0 to 48%. The objective was to study the prevalence of TRAb in patients with CT and hypothyroidism and to correlate it with gender, age, thyroid dimensions, TSH levels, and autoimmune diseases.

METHODS

The study comprised 245 patients with CT and hypothyroidism (median age 42 years, 193 females, 52 males) and 123 Italian healthy subjects matched for sex and age as controls. TRAb were tested with ELISA using a >2.5 IU/L cut off for positivity. TSHR blocking (TBAb) and TSHR stimulating autoantibodies (TSAb) were measured in 12 TRAb-positive patients using bioassays with Chinese hamster ovary (CHO) cells expressing wild-type or R255D-mutated TSHR.

RESULTS

TRAb positivity was found in 32/245 (13.1%) patients and significantly correlated (p<0.05) with TSH levels. TRAb positivity was significantly higher in males vs. females (p=0.034), in females 16-45 years of age vs. >45 years of age (p<0.05) and in patients with reduced vs. normal/increased thyroid dimensions (p<0.05). Linear regression analysis showed a correlation between TRAb concentrations with age (p<0.05) and TRAb concentrations with TSH (p<0.01). In bioassay with TSHR-R255D all 12 patients tested were TBAb-positive while 33% were also TSAb-positive suggesting the presence of a mixture of TRAbs with different biological activities in some patients.

CONCLUSIONS

TRAb have been found in patients with CT and hypothyroidism. A mixture of TBAb and TSAb was found in some patients and this may contribute to the pathogenesis of thyroid dysfunction during the course of the disease.

Thyroid Disease in Pregnancy: A Descriptive Review of Guidelines

Importance

Thyroid disorders represent one of the most frequent complications of pregnancy associated with adverse obstetric, fetal, and neonatal outcomes, especially in case of delayed diagnosis and suboptimal management.

Objective

The aim of this study was to review and compare the recommendations of the most recently published guidelines on the diagnosis and management of these common conditions.

Evidence Acquisition

A descriptive review of guidelines from the Endocrine Society, the European Thyroid Association, the Royal Australian and New Zealand College of Obstetricians and Gynecologists, the American Thyroid Association, and the American College of Obstetricians and Gynecologists on thyroid disease in pregnancy was carried out.

Results

There is an overall consensus regarding the diagnosis of overt and subclinical hypothyroidism and hyperthyroidism in pregnancy using the pregnancy-specific reference ranges and the definition of postpartum thyroiditis. The reviewed guidelines unanimously discourage universal screening for thyroid function abnormalities before and during pregnancy and support targeted screening of high-risk patients by measuring serum thyroid-stimulating hormone levels. Moreover, they all highlight the need of treating overt hypothyroidism and hyperthyroidism, not only during pregnancy, but also before conception, suggesting similar management policies and treatment targets. There is also agreement regarding the management of gestational transient hyperthyroidism with hyperemesis gravidarum, suspected fetal thyrotoxicosis, postpartum thyroiditis, and thyroid malignancy. Scanning or treating with radioactive iodine is contraindicated during pregnancy and breastfeeding. On the other hand, there is controversy on the management of subclinical thyroid disease, thyroid function surveillance protocols, and iodine nutrition recommendations. Of note, the American College of Obstetricians and Gynecologists makes some specific recommendations on the treatment of thyroid storm and thyrotoxic heart failure in pregnant women, whereas the American Thyroid Association makes a special reference to the management of women with thyroid cancer.

Conclusions

As the disorders of the thyroid gland affect a significant proportion of pregnant women, it is of paramount importance to develop uniform international evidence-based protocols for their accurate diagnosis and optimal management, in order to safely guide clinical practice and eventually improve perinatal outcomes.

Antithyroid drug therapy for Graves’ disease

Background: Graves’ disease is the most common cause of hyperthyroidism which is caused by stimulating autoantibodies against thyroid-stimulating hormone receptor. There is no etiology-specific treatment for Graves’ disease.Current Concepts: Graves’ disease can be treated with antithyroid drugs (ATDs), radioactive iodine, or thyroidectomy. ATDs are the most preferred first-line therapy, because they do not cause either permanent hypothyroidism or exacerbation of orbitopathy, despite low remission rate. ATDs have serious adverse reactions including agranulocytosis and fulminant hepatic necrosis requiring liver transplantation. Methimazole (MMI) is recommended in every patient starting ATD therapy, except during the first trimester of pregnancy and in cases of thyroid storm, because of relatively lower incidence and severity of serious adverse reactions compared with propylthiouracil. Treatment should be continued for 12 to 18 months, then discontinued if the levels of thyroid-stimulating hormone and thyroid-stimulating hormone receptor antibodies are normalized. In cases of relapse of hyperthyroidism, radioactive iodine or thyroidectomy can be recommended for definitive therapy; however, recent studies support longer-term maintenance of low dose MMI as a favorable alternative therapy. All ATDs may induce congenital anomalies when exposed during early pregnancy. Every female patient of reproductive age should be advised to postpone pregnancy until their thyroid function is maintained within normal range and to stop ATDs when pregnancy is confirmed to avoid the risk of congenital anomalies.Discussion and Conclusion: Longer-term low dose MMI therapy can be a good choice for Graves’ hyperthyroidism with relapse. Before pregnancy, hyperthyroidism should be controlled to stop ATDs during pregnancy.

Dose-Dependent Influence of Antithyroid Drugs on the Difference in Free Thyroxine Levels between Mothers with Graves' Hyperthyroidism and Their Neonates

BACKGROUND

Several guidelines have recommended that the use of the lowest effective dose of antithyroid drugs (ATDs) that maintains maternal serum free thyroxine (FT4) levels at or moderately above the upper limit of the reference range is appropriate for fetal euthyroid status. However, little is known about whether ATD dosage affects the difference in serum FT4 levels between the mother and neonate. We conducted a retrospective study at a tertiary hospital in Japan to investigate the dose-dependent influence of ATDs on both maternal and fetal thyroid hormone status.

MATERIALS AND METHODS

We retrospectively examined 62 pregnant women who delivered between 2007 and 2016 and were treated for Graves' hyperthyroidism with ATD at any stage during pregnancy. We selected individuals whose data on maternal FT4 level within 4 weeks of their deliveries and cord FT4 level of their infants at the time of delivery were available. Those with multiple pregnancies, iodine or glucocorticoid treatment, and fetal goiter detected by ultrasonography were excluded.

RESULTS

After the exclusion criteria were applied, we recruited 40 individuals. The cord FT4 levels were significantly lower than the maternal FT4 levels in patients treated with high-dosage ATDs (methimazole >5 mg daily or propylthiouracil >100 mg daily). However, there were no significant differences between maternal and cord FT4 levels in patients treated with low-dosage ATDs (methimazole ≤5 mg daily or propylthiouracil ≤100 mg daily). We selected 35 individuals whose data on maternal thyrotropin receptor-binding inhibitory immunoglobulin (TBII) level were available. Multiple linear regression analysis adjusted for ATD dosage, maternal TBII level, and gestational period found that ATD dosage was a significant predictor of the difference in serum FT4 levels between the mother and neonate. In terms of maternal complications, multiple logistic regression analysis identified maternal free triiodothyronine (FT3) level as a significant predictor of the incidence of preterm delivery.

CONCLUSIONS

We found a dose-dependent influence of ATDs on the difference in serum FT4 levels between mothers with Graves' hyperthyroidism and their neonates. Further studies to evaluate the optimal target FT4 and FT3 levels for the mother and neonate during pregnancy may improve the outcome of pregnant women with Graves' hyperthyroidism.

Management of Severe Graves' Hyperthyroidism in Pregnancy Following Immune Reconstitution Therapy in Multiple Sclerosis

CONTEXT

Alemtuzumab (ALZ), a CD52 monoclonal antibody, is highly efficacious in multiple sclerosis; however, side effects are common. Autoimmune thyroid disease (Graves' disease and Hashimoto thyroiditis) is a well-known complication of ALZ. Treatment of ALZ-induced Graves' disease can be challenging, and even more difficult during pregnancy.

CASE DESCRIPTION

We present a case of severe ALZ-induced Graves' disease with a rapid increase in thyrotropin receptor antibodies (TRAb 240 IU/L) and thyrotoxicosis in early pregnancy. Treatment with high doses of antithyroid medication was needed. There was high risk of both fetal and neonatal thyrotoxicosis. Serial fetal sonography showed normal development. The newborn baby presented high levels of TRAb (240 IU/L) and developed neonatal thyrotoxicosis on day 8. Adequate monitoring, treatment, and follow-up of the newborn baby ensured normal thyroid function until disappearance of TRAb 6 weeks after birth.

CONCLUSION

Multiple sclerosis patients treated with ALZ may develop severe Graves' disease with an increased risk of both fetal and neonatal thyrotoxicosis. Close follow-up with a multidisciplinary approach is needed to ensure a healthy outcome.

Hemodynamic changes in neonates born to mothers with Graves' disease

PURPOSE

Cardiac insufficiency is a major morbidity in neonatal hyperthyroidism. It is important to assess the hemodynamics in neonates born to mothers with Graves' disease (GD). This study prospectively evaluated the hemodynamic changes in neonates born to mothers with GD.

METHODS

Overall, 80 newborns were enrolled. Thirty-six neonates were born to mothers with GD who were positive for thyroid-stimulating hormone (TSH) receptor antibody (TRAb), and 44 were born to mother negative for TRAb. The serum levels of TSH, free triiodothyronine (FT₃), free thyroxine (FT₄), and N-terminal-pro-B-type natriuretic peptide (NT-proBNP), the cardiac output, and cardiac index (CI) evaluated by echocardiography were compared between the two groups at several postnatal points (day of delivery and 5, 10, and 30 days of life).

RESULTS

The TRAb-positive newborns had higher FT₄ levels and CI on Day 5 (both p < 0.05) and higher FT₃ (p < 0.05) and FT₄ levels (p < 0.01) and CI (p < 0.01) but lower TSH levels (p < 0.05) on Day 10 than the TRAb-negative newborns. The TRAb-positive newborns had significantly higher NT-proBNP levels on Days 5 (median 752 vs. 563 pg/mL, p = 0.034) and 10 (median 789 vs. 552 pg/mL, p = 0.002) than the TRAb-negative newborns.

CONCLUSIONS

Hemodynamic changes in neonates born to TRAb-positive mothers with GD resulted in a higher CI and NT-proBNP levels than in those with TRAb-negative mothers from postnatal days 5 to 10.

Variations in the Antithyroid Antibody Titre During Pregnancy and After Delivery

Background

Immunosuppression occurs during pregnancy, and the antithyroid antibody titre drops, rebounding after delivery. We aimed to determine variations in antithyroid antibody titres during pregnancy and after delivery.

Methods

This retrospective study was conducted in a single centre. Antibody titres of 142 patients were measured to assess variations in the levels of thyroid-stimulating hormone receptor antibodies (TRAbs), thyroid peroxidase antibodies (TPOAbs), and thyroid globulin antibodies (TgAbs). We compared the titres of each antibody between adjacent time periods (eg, first trimester (T1) vs second trimester (T2), T2 vs third trimester (T3), T3 vs the postpartum period (PP)) by paired t-test or the Wilcoxon test. Then, we analysed data from patients with complete laboratory examination results in all four periods with the Friedman test, performing comparisons among groups.

Results

In the TgAb group, significant differences existed between T1 and T2 and between T2 and T3 in the LT4 subgroup and between T1 and T2 in the no-medication subgroup. In the TRAb group, significant differences existed between T1 and T2 in the LT4 subgroup. In the TPOAb group, significant differences existed among each group in the LT4 subgroup, and there were significant differences between T1 and T2 and between T2 and T3 in the no-medication subgroup. The Friedman test showed that the P-values were 0.013 and 0.004 in the LT4 and no-medication subgroups of the TgAb group, respectively; 0.122 in the LT4 subgroup of the TRAb group; and <0.001 and 0.272 in the LT4 and no-medication subgroups of the TPOAb group, respectively. In the LT4 subgroup of the TgAb group, the P-values for comparisons of time periods were 0.602 between T1 and T2, 0.602 between T2 and T3, 0.006 between T1 and T3, and 0.602 between T3 and PP. In the no-medication subgroup of the TgAb group, the P-values were 0.078 between T1 and T2, 1.000 between T2 and T3, 0.011 between T1 and T3, and 0.078 between T3 and PP. In the LT4 subgroup of the TPOAb group, the P-values were 0.09 between T1 and T2, 0.014 between T2 and T3, <0.001 between T1 and T3, and 0.772 between T3 and PP.

Conclusion

We can conclude that the TgAb and TPOAb titres dropped during pregnancy.

Pregnancy outcomes in women with preexisting thyroid diseases: a French cohort study

Women with thyroid diseases at the beginning of pregnancy may have suboptimal thyroid hormone levels because of potential difficulties in compensating for the physiological thyroid hormone changes occurring in pregnancy. Our objective was to study the association between preexisting thyroid diseases, pregnancy complications, and neonatal anthropometry. In total, 16,395 women from the ELFE French longitudinal birth cohort were included, and 273 declared pre-pregnancy thyroid diseases. Associations were investigated with multivariable regression models, with adjustment for relevant potential confounders. Body mass index (BMI) was additionally adjusted for in a second stage. As compared with other women, women with pre-pregnancy thyroid diseases were more frequently obese (19.6% vs. 9.8%) and had greater odds of gestational diabetes development (odds ratio [OR] = 1.58 [95% confidence interval [CI] 1.08, 2.30]) or had undergone treatment for infertility (OR = 1.57 [95% CI 1.07, 2.31]). After adjustment for BMI, the association with gestational diabetes was no longer significant (OR = 1.27 [95% CI 0.86, 1.88]). After excluding women with another medical history, those with pre-pregnancy thyroid diseases had increased odds of premature rupture of membranes (OR = 1.51 [95% CI 1.01, 2.25]). Children born from mothers with hypothyroidism before conception due to a disease or as a potential side effect of treatment had a smaller head circumference at birth than other children (β = -0.23 [95% CI -0.44, -0.01] cm). In conclusion, pre-pregnancy thyroid diseases were associated with risk of infertility treatment, gestational diabetes, and premature rupture of membranes. The association between history of hypothyroidism and moderate adverse effects on fetal head circumference growth needs replication.

Management of thyrotoxicosis during pregnancy

Thyrotoxicosis during pregnancy should be adequately managed and controlled to prevent maternal and fetal complications. The evaluation of thyroid function in pregnant women is challenged by the physiological adaptations associated with pregnancy, and the treatment with antithyroid drugs (ATD) raises concerns for the pregnant woman and the fetus. Thyrotoxicosis in pregnant women is mainly of autoimmune origin, and the measurement of thyroid stimulating hormone-receptor antibodies (TRAb) plays a key role. TRAb helps to distinguish the hyperthyroidism of Graves' disease from gestational hyperthyroidism in early pregnancy, and to evaluate the risk of fetal and neonatal hyperthyroidism in late pregnancy. Furthermore, the measurement of TRAb in early pregnancy is recommended to evaluate the need for ATD during the teratogenic period of pregnancy. Observational studies have raised concern about the risk of birth defects associated with the use of ATD in early pregnancy and challenged the clinical management and choice of treatment.

Fetal goiter identified in a pregnant woman with triiodothyronine-predominant graves' disease: a case report

BACKGROUND

Approximately 10% of all Graves' disease cases are triiodothyronine (T3)-predominant. T3-predominance is characterized by higher T3 levels than thyroxine (T4) levels. Thyroid stimulating hormone receptor autoantibody (TRAb) levels are higher in T3-predominant Graves' disease cases than in non-T3-predominant Graves' disease cases. Treatment with oral drugs is difficult. Here, we report a case of fetal goiter in a pregnant woman with T3-predominant Graves' disease.

CASE PRESENTATION

A 31-year-old woman had unstable thyroid function during the third trimester of pregnancy, making it impossible to reduce her dosage of antithyroid medication. She was admitted to our hospital at 34 weeks of gestation owing to hydramnios and signs of threatened premature labor, and fetal goiter (thyromegaly) was detected. The dose of her antithyroid medication was reduced, based on the assumption that it had migrated to the fetus. Subsequently, the fetal goiter decreased in size, and the hydramnios improved. The patient underwent elective cesarean delivery at 36 weeks and 5 days of gestation. The infant presented with temporary symptoms of hyperthyroidism that improved over time.

CONCLUSIONS

The recommended perinatal management of Graves' disease is to adjust free T4 within a range from the upper limit of normal to a slightly elevated level in order to maintain the thyroid function of the fetus. However, in T3-predominant cases, free T4 levels may drop during the long-term course of the pregnancy owing to attempts to control the mother's symptoms of thyrotoxicosis. Little is known about the perinatal management and appropriate therapeutic strategy for T3-predominant cases and fetal goiter. Therefore, further investigation is necessary.

Maternal thyroid disease and its effects on the fetus and perinatal outcomes

Thyroid disease is common in women of childbearing age and can have significant effects on the development of the fetus and perinatal outcomes. Maternal thyroid hormone is critical for proper fetal neurodevelopment, and the fetus relies on thyroid hormone from its mother for the first half of pregnancy. Both overt maternal hypothyroidism and overt maternal hyperthyroidism have been shown to be associated with adverse effects on central nervous system gray matter and neurocognitive development of offspring as well as increased obstetrical risks. Treatment of overt thyroid conditions improves outcomes. Subclinical maternal hypothyroidism may increase adverse neurocognitive and obstetrical outcomes although data are conflicting. To date, treatment of subclinical hypothyroidism has not shown benefit. Subclinical hyperthyroidism is well tolerated in pregnancy. Thyroid autoantibodies alone may also affect neurodevelopment and obstetrical outcomes; however, recent data have shown no improvement with levothyroxine treatment. Several rare maternal genetic thyroid conditions can affect the fetus including a thyroid-stimulating hormone receptor mutation leading to hypersensitivity to human chorionic gonadotropin and thyroid hormone resistance. The thyroid plays a crucial role in fetal health and understanding it is important for optimal care.

Hyperthyroidism and Pregnancy

Clinical hyperthyroidism affects 0.1% to 0.4% of pregnancies. Gestational thyrotoxicosis is due to homology of the structure of TSH and HCG, which weakly stimulates the TSH receptor. Graves' disease (GD) most commonly causes clinically significant hyperthyroidism. Given concerns for teratogenicity from antithyroid drugs, these may be discontinued in low-risk GD patients. High-risk patients are treated with propylthiouracil in the first trimester then may transition to methimazole. Surgery is reserved for special circumstances; radioactive iodine is contraindicated. In late pregnancy, GD may remit; postpartum relapse is common. Measurement of serum thyrotropin receptor antibodies identifies pregnancies at-risk for fetal and neonatal hyperthyroidism.

Hyperthyroidism in the pregnant woman: Maternal and fetal aspects

Hyperthyroidism during pregnancy is uncommon. Nonetheless, prompt identification and adequate management of hyperthyroidism in a pregnant woman is essential, because uncontrolled thyrotoxicosis significantly increases the risk of maternal and fetal complications. Also, fetal prognosis may be affected by the transplacental passage of maternal thyroid stimulating antibodies or thyrostatic agents, both of which may disrupt fetal thyroid function. Birth defects have been reported in association with the use of antithyroid drugs during early pregnancy. Although rarely, offspring of mothers with Graves’ disease may develop fetal/neonatal hyperthyroidism, the management of which requires a close collaboration between endocrinologists, obstetricians, and neonatologists.

Because of the above considerations, the management of pregnant and lactating women with hyperthyroidism requires special care, bearing in mind that both maternal thyroid excess per se and related treatments may adversely affect the newborn’s health.

In this review we discuss the diagnosis and management of hyperthyroidism in pregnancy, along with the impact of thyrotoxicosis and medications on fetal outcome.

Chronic diseases in the children of women with maternal thyroid dysfunction: a nationwide cohort study

Objective

Maternal thyroid disease (TD) during pregnancy is associated with adverse birth outcomes, but little is known on its long-term outcomes. We aimed to examine if children born to mothers with TD have increased disease risk during childhood and adolescence.

Patients and methods

A register-based cohort study was conducted on all live born children in Denmark from 1989 to 2013, including the association between maternal TD during pregnancy and somatic and psychiatric diseases in the children. Cox proportional hazards models were used to compute hazard ratios (HRs) according to the type of maternal TD, Graves’ disease, and Hashimoto’s thyroiditis.

Results

A total of 2,618 children were born to women with Graves’ disease, 760 to women with Hashimoto’s thyroiditis (exposed), and 1,557,577 to women without any TD (unexposed). The median follow-up time for children born to mothers with Graves’ disease was 9.3 years (25/75 percentile 5.4/13.9 years) and with Hashimoto’s thyroiditis was 4.8 years (25/75 percentile 2.5/8.2 years). In children exposed to maternal Graves’ disease in utero, the adjusted HR of TD was 12.83 (95% CI, 9.74–16.90), Graves’ disease was 34.3 (95% CI, 20.23–58.35), and type 1 was diabetes 2.47 (95% CI, 1.46–4.18). In children exposed to maternal Hashimoto’s thyroiditis, the adjusted HR of Hashimoto’s thyroiditis was 24.04 (95% CI, 5.89–97.94).

Conclusion

Our data suggest that children born to women with Graves’ disease and Hashimoto’s thyroiditis have excess long-term morbidities in childhood and adolescence. We particularly found an increased risk of any TD and type 1 diabetes to be diagnosed in children exposed in utero to Graves’ disease. These novel findings are relevant for pediatricians, stressing the importance of history of maternal disease when evaluating children with suspected endocrine disorders.

2018 European Thyroid Association Guideline for the Management of Graves' Hyperthyroidism

Graves' disease (GD) is a systemic autoimmune disorder characterized by the infiltration of thyroid antigen-specific T cells into thyroid-stimulating hormone receptor (TSH-R)-expressing tissues. Stimulatory autoantibodies (Ab) in GD activate the TSH-R leading to thyroid hyperplasia and unregulated thyroid hormone production and secretion. Diagnosis of GD is straightforward in a patient with biochemically confirmed thyrotoxicosis, positive TSH-R-Ab, a hypervascular and hypoechoic thyroid gland (ultrasound), and associated orbitopathy. In GD, measurement of TSH-R-Ab is recommended for an accurate diagnosis/differential diagnosis, prior to stopping antithyroid drug (ATD) treatment and during pregnancy. Graves' hyperthyroidism is treated by decreasing thyroid hormone synthesis with the use of ATD, or by reducing the amount of thyroid tissue with radioactive iodine (RAI) treatment or total thyroidectomy. Patients with newly diagnosed Graves' hyperthyroidism are usually medically treated for 12-18 months with methimazole (MMI) as the preferred drug. In children with GD, a 24- to 36-month course of MMI is recommended. Patients with persistently high TSH-R-Ab at 12-18 months can continue MMI treatment, repeating the TSH-R-Ab measurement after an additional 12 months, or opt for therapy with RAI or thyroidectomy. Women treated with MMI should be switched to propylthiouracil when planning pregnancy and during the first trimester of pregnancy. If a patient relapses after completing a course of ATD, definitive treatment is recommended; however, continued long-term low-dose MMI can be considered. Thyroidectomy should be performed by an experienced high-volume thyroid surgeon. RAI is contraindicated in Graves' patients with active/severe orbitopathy, and steroid prophylaxis is warranted in Graves' patients with mild/active orbitopathy receiving RAI.

Graves' hyperthyroidism in pregnancy: a clinical review

Background

Graves’ hyperthyroidism affects 0.2% of pregnant women. Establishing the correct diagnosis and effectively managing Graves’ hyperthyroidism in pregnancy remains a challenge for physicians.

Main

The goal of this paper is to review the diagnosis and management of Graves’ hyperthyroidism in pregnancy. The paper will discuss preconception counseling, etiologies of hyperthyroidism, thyroid function testing, pregnancy-related complications, maternal management, including thyroid storm, anti-thyroid drugs and the complications for mother and fetus, fetal and neonatal thyroid function, neonatal management, and maternal post-partum management.

Conclusion

Establishing the diagnosis of Graves’ hyperthyroidism early, maintaining euthyroidism, and achieving a serum total T4 in the upper limit of normal throughout pregnancy is key to reducing the risk of maternal, fetal, and newborn complications. The key to a successful pregnancy begins with preconception counseling.

Maternal Thyrotropin Receptor Antibody Concentration and the Risk of Fetal and Neonatal Thyrotoxicosis: A Systematic Review

BACKGROUND

In pregnant women with Graves' disease, maternal thyrotropin receptor antibodies (TRAb) can cross the placenta and induce fetal or neonatal thyrotoxicosis. Symptoms of fetal thyrotoxicosis are tachycardia, intrauterine growth restriction, and intra-uterine death. Recommendations on an upper limit of TRAb concentrations below which intensive fetal monitoring can be safely omitted vary between different guidelines. The objective of this study was to define an evidence-based cutoff level for maternal TRAb necessitating additional fetal monitoring during pregnancy.

METHODS

A literature search was performed to identify studies on pregnant women with Graves' disease and fetal and/or neonatal thyrotoxicosis. Only studies that reported TRAb were included.

RESULTS

From a total of 229 identified titles, 20 articles could be included in the analysis. A total of 53 cases of fetal and/or neonatal thyrotoxicosis were described. The lowest level of maternal TRAb leading to neonatal thyrotoxicosis was 4.4 U/L, which corresponds to 3.7 times the upper limit of normal. The level of evidence for this threshold is moderate to low.

CONCLUSION

In women with Graves' disease, intensive fetal monitoring is recommended when maternal TRAb concentrations are >3.7 times the upper limit of normal. This cutoff level should be interpreted with caution, since evidence is limited.

Antithyroid drug therapy in pregnancy: a review of guideline recommendations

The antithyroid drugs, Carbimazole, Methimazole, and Propylthiouracil remain the mainstay of Graves' disease management in pregnancy. A series of Clinical Practice Guidelines aimed at optimising fetal and maternal outcomes in women with Graves' disease have been published in recent years. Areas covered: This review examines existing guideline recommendations on antithyroid drug management of Graves' disease in pregnancy. Expert commentary: Recent guidelines have been shaped by expanding knowledge of the adverse effect profiles of antithyroid drugs on the developing fetus. A core management strategy is to limit fetal exposure to excess thyroid hormones and to curtail adverse drug effects through effective preconception and peri-conception management. Propylthiouracil is the recommended treatment in the first trimester of pregnancy but there is uncertainty regarding antithyroid drug choices in women who continue to require treatment in later pregnancy. Further studies are needed to fully evaluate the risks of congenital anomalies following intrauterine thionamide exposure.

2017 Guidelines of the American Thyroid Association for the Diagnosis and Management of Thyroid Disease During Pregnancy and the Postpartum

BACKGROUND

Thyroid disease in pregnancy is a common clinical problem. Since the guidelines for the management of these disorders by the American Thyroid Association (ATA) were first published in 2011, significant clinical and scientific advances have occurred in the field. The aim of these guidelines is to inform clinicians, patients, researchers, and health policy makers on published evidence relating to the diagnosis and management of thyroid disease in women during pregnancy, preconception, and the postpartum period.

METHODS

The specific clinical questions addressed in these guidelines were based on prior versions of the guidelines, stakeholder input, and input of task force members. Task force panel members were educated on knowledge synthesis methods, including electronic database searching, review and selection of relevant citations, and critical appraisal of selected studies. Published English language articles were eligible for inclusion. The American College of Physicians Guideline Grading System was used for critical appraisal of evidence and grading strength of recommendations. The guideline task force had complete editorial independence from the ATA. Competing interests of guideline task force members were regularly updated, managed, and communicated to the ATA and task force members.

RESULTS

The revised guidelines for the management of thyroid disease in pregnancy include recommendations regarding the interpretation of thyroid function tests in pregnancy, iodine nutrition, thyroid autoantibodies and pregnancy complications, thyroid considerations in infertile women, hypothyroidism in pregnancy, thyrotoxicosis in pregnancy, thyroid nodules and cancer in pregnant women, fetal and neonatal considerations, thyroid disease and lactation, screening for thyroid dysfunction in pregnancy, and directions for future research.

CONCLUSIONS

We have developed evidence-based recommendations to inform clinical decision-making in the management of thyroid disease in pregnant and postpartum women. While all care must be individualized, such recommendations provide, in our opinion, optimal care paradigms for patients with these disorders.

Thyroid-Stimulating Hormone Receptor Antibodies in Pregnancy: Clinical Relevance

Graves' disease is the most common cause of thyrotoxicosis in women of childbearing age. Approximately 1% of pregnant women been treated before, or are being treated during pregnancy for Graves' hyperthyroidism. In pregnancy, as in not pregnant state, thyroid-stimulating hormone (TSH) receptor (TSHR) antibodies (TRAbs) are the pathogenetic hallmark of Graves' disease. TRAbs are heterogeneous for molecular and functional properties and are subdivided into activating (TSAbs), blocking (TBAbs), or neutral (N-TRAbs) depending on their effect on TSHR. The typical clinical features of Graves' disease (goiter, hyperthyroidism, ophthalmopathy, dermopathy) occur when TSAbs predominate. Graves' disease shows some peculiarities in pregnancy. The TRAbs disturb the maternal as well as the fetal thyroid function given their ability to cross the placental barrier. The pregnancy-related immunosuppression reduces the levels of TRAbs in most cases although they persist in women with active disease as well as in women who received definitive therapy (radioiodine or surgery) before pregnancy. Changes of functional properties from stimulating to blocking the TSHR could occur during gestation. Drug therapy is the treatment of choice for hyperthyroidism during gestation. Antithyroid drugs also cross the placenta and therefore decrease both the maternal and the fetal thyroid hormone production. The management of Graves' disease in pregnancy should be aimed at maintaining euthyroidism in the mother as well as in the fetus. Maternal and fetal thyroid dysfunction (hyperthyroidism as well as hypothyroidism) are in fact associated with several morbidities. Monitoring of the maternal thyroid function, TRAbs measurement, and fetal surveillance are the mainstay for the management of Graves' disease in pregnancy. This review summarizes the biochemical, immunological, and therapeutic aspects of Graves' disease in pregnancy focusing on the role of the TRAbs in maternal and fetal function.

ENDOCRINOLOGY IN PREGNANCY: Pregnancy and the incidence, diagnosing and therapy of Graves' disease

Thyroid hormones are essential developmental factors, and Graves' disease (GD) may severely complicate a pregnancy. This review describes how pregnancy changes the risk of developing GD, how early pregnancy by several mechanisms leads to considerable changes in the results of the thyroid function tests used to diagnose hyperthyroidism, and how these changes may complicate the diagnosing of GD. Standard therapy of GD in pregnancy is anti-thyroid drugs. However, new studies have shown considerable risk of birth defects if these drugs are used in specific weeks of early pregnancy, and this should be taken into consideration when planning therapy and control of women who may in the future become pregnant. Early pregnancy is a period of major focus in GD, where pregnancy should be diagnosed as soon as possible, and where important and instant change in therapy may be warranted. Such change may be an immediate stop of anti-thyroid drug therapy in patients with a low risk of rapid relapse of hyperthyroidism, or it may be an immediate shift from methimazole/carbimazole (with risk of severe birth defects) to propylthiouracil (with less risk), or maybe to other types of therapy where no risk of birth defects have been observed. In the second half of pregnancy, an important concern is that not only the mother with GD but also her foetus should have normal thyroid function.

2016 American Thyroid Association Guidelines for Diagnosis and Management of Hyperthyroidism and Other Causes of Thyrotoxicosis

BACKGROUND

Thyrotoxicosis has multiple etiologies, manifestations, and potential therapies. Appropriate treatment requires an accurate diagnosis and is influenced by coexisting medical conditions and patient preference. This document describes evidence-based clinical guidelines for the management of thyrotoxicosis that would be useful to generalist and subspecialty physicians and others providing care for patients with this condition.

METHODS

The American Thyroid Association (ATA) previously cosponsored guidelines for the management of thyrotoxicosis that were published in 2011. Considerable new literature has been published since then, and the ATA felt updated evidence-based guidelines were needed. The association assembled a task force of expert clinicians who authored this report. They examined relevant literature using a systematic PubMed search supplemented with additional published materials. An evidence-based medicine approach that incorporated the knowledge and experience of the panel was used to update the 2011 text and recommendations. The strength of the recommendations and the quality of evidence supporting them were rated according to the approach recommended by the Grading of Recommendations, Assessment, Development, and Evaluation Group.

RESULTS

Clinical topics addressed include the initial evaluation and management of thyrotoxicosis; management of Graves' hyperthyroidism using radioactive iodine, antithyroid drugs, or surgery; management of toxic multinodular goiter or toxic adenoma using radioactive iodine or surgery; Graves' disease in children, adolescents, or pregnant patients; subclinical hyperthyroidism; hyperthyroidism in patients with Graves' orbitopathy; and management of other miscellaneous causes of thyrotoxicosis. New paradigms since publication of the 2011 guidelines are presented for the evaluation of the etiology of thyrotoxicosis, the management of Graves' hyperthyroidism with antithyroid drugs, the management of pregnant hyperthyroid patients, and the preparation of patients for thyroid surgery. The sections on less common causes of thyrotoxicosis have been expanded.

CONCLUSIONS

One hundred twenty-four evidence-based recommendations were developed to aid in the care of patients with thyrotoxicosis and to share what the task force believes is current, rational, and optimal medical practice.

Managing hyperthyroidism in pregnancy: current perspectives

Hyperthyroidism in women who are of childbearing age is predominantly of autoimmune origin and caused by Graves' disease. The physiological changes in the maternal immune system during a pregnancy may influence the development of this and other autoimmune diseases. Furthermore, pregnancy-associated physiological changes influence the synthesis and metabolism of thyroid hormones and challenge the interpretation of thyroid function tests in pregnancy. Thyroid hormones are crucial regulators of early development and play an important role in the maintenance of a normal pregnancy and in the development of the fetus, particularly the fetal brain. Untreated or inadequately treated hyperthyroidism is associated with pregnancy complications and may even program the fetus to long-term development of disease. Thus, hyperthyroidism in pregnant women should be carefully managed and controlled, and proper management involves different medical specialties. The treatment of choice in pregnancy is antithyroid drugs (ATDs). These drugs are effective in the control of maternal hyperthyroidism, but they all cross the placenta, and so need careful management and control during the second half of pregnancy considering the risk of fetal hyper- or hypothyroidism. An important aspect in the early pregnancy is that the predominant side effect to the use of ATDs in weeks 6-10 of pregnancy is birth defects that may develop after exposure to available types of ATDs and may be severe. This review focuses on four current perspectives in the management of overt hyperthyroidism in pregnancy, including the etiology and incidence of the disease, how the diagnosis is made, the consequences of untreated or inadequately treated disease, and finally how to treat overt hyperthyroidism in pregnancy.

Should All Women Be Screened for Thyroid Dysfunction in Pregnancy?

The subject of universal thyroid screening in pregnancy generates impassioned debate. Thyroid dysfunction is common, has significant adverse implications for fetal and maternal well-being, is readily detectable and can be effectively and inexpensively treated. Furthermore, the currently recommended case-finding strategy does not identify a substantially proportion of women with thyroid dysfunction thus favoring universal screening. On the other hand subclinical thyroid dysfunction forms the bulk of gestational thyroid disorders and the paucity of high-level evidence to support correction of these asymptomatic biochemical abnormalities weighs against universal screening. This review critically appraises the literature, examines the pros and cons of universal thyroid screening in pregnancy, highlighting the now strong case for implementing universal screening and explores strategies for its implementation.

Rethinking antithyroid drugs in pregnancy

Uncontrolled hyperthyroidism in pregnancy poses a risk to both mother and foetus, and the optimal treatment strategy in this setting remains elusive. Instigation of pharmacological therapy or an alternative intervention during pregnancy requires careful consideration, and the evidence that has underpinned our choice of antithyroid drug has not been robust. Recent research developments have prompted us to question our practice, and reconsider our approach to managing this patient group.

[Neonatal hyperthyroidism and maternal Graves disease]

The onset of Graves disease during pregnancy exposes the neonate to the risk of hyperthyroidism. The newborn must be monitored and treatment modalities known to ensure early treatment of the newborn. We report on the case of an infant born at term of a mother with Graves disease discovered during pregnancy. He was asymptomatic during the first days of life, before declaring the disease. Neonatal hyperthyroidism was confirmed by hormonal assays. Hyperthyroidism was treated with antithyroid drugs and propranolol with a satisfactory clinical and biological course. Neonatal hyperthyroidism should be systematically sought in infants born to a mother with Graves disease. The absence of clinical signs during the first days of life does not exclude the diagnosis. The duration of monitoring should be decided according to the results of the first hormonal balance tests.

Thyroid autoimmunity in pregnancy and its influences on maternal and fetal outcome in Iran (a prospective study)

AIM OF THE STUDY

Thyroid dysfunction and autoimmunity are common problems in women of child-bearing age. It could be associated with pregnancy morbidities in the mother and fetus. Due to lack of sufficient data about the prevalence of thyroid autoimmunity in pregnant women in Iran, and controversies about its complications on pregnancy outcomes, this study was conducted.

MATERIALS AND METHODS

This is a prospective study on 600 singleton pregnant women in 15-28 weeks of pregnancy; they were residents of Fars province. We evaluated the prevalence of preeclampsia, intra-uterine growth retardation (IUGR), preterm delivery and low Apgar score and their association with TSH, thyroid peroxidase (TPO), and thyroglobulin (Tg) antibodies.

RESULTS

Prevalence of anti-TPO and anti-Tg positivity is 12.8% and 8.5% among Iranian pregnant women. Mothers with either positive TPO or Tg antibody have a higher risk of preeclampsia (p = 0.019), preterm delivery (p < 0.001), IUGR (p < 0.001), and low first minute Apgar score (p < 0.001). This association was independent of thyroid dysfunction for preterm delivery (RR = 5, p < 0.001), and low Apgar score neonates (RR = 8.8, p < 0.001), but this association for preeclampsia was due to thyroid dysfunction (RR = 3.7, p = 0.003). About IUGR in either TPO or Tg positive mothers, this association results from the additive effect of thyroid dysfunction and thyroid autoimmunity (RR = 8.3, p < 0.001). Cesarean section delivery was significantly higher in abnormal TSH/positive anti-Tg mothers (p = 0.045).

CONCLUSION

Thyroid autoimmunity independent of thyroid dysfunction could have significant adverse outcomes in the mother and fetus. Further investigation should be done to reveal the significance of screening and treating the thyroid autoimmunity during pregnancy.

A case of fetal hyperthyroidism treated with maternal administration of methimazole

Prenatal ultrasonography of a pregnant woman with a past history of total thyroidectomy for Graves' disease detected fetal tachycardia, fetal growth restriction and oligohydramnios at 30 weeks gestation. Because a high titer of thyroid-stimulating hormone receptor antibody was noted in maternal serum and the fetal goiter was detected on ultrasonography, fetal hyperthyroidism was strongly suspected and subsequently confirmed with cordocentesis at 31 weeks gestation. After treatment of fetal hyperthyroidism through oral maternal administration of methimazole (MMI) starting at 33 weeks gestation, fetal heart rate and amniotic fluid volume returned to normal ranges. Complete resolution of the fetal goiter was observed at 35 weeks gestation. A male infant was born at 35 weeks 6 days gestation via cesarean section in the absence of thyrotoxic findings; however, cord blood chemical analysis at birth indicated iatrogenic fetal hypothyroidism. In the present report, maternal therapy using MMI to resolve symptoms of fetal thyrotoxicosis, including fetal tachycardia and oligohydramnios, was successfully conducted.

Predictive value of maternal second-generation thyroid-binding inhibitory immunoglobulin assay for neonatal autoimmune hyperthyroidism

CONTEXT

Hyperthyroidism occurs in 1% of neonates born to mothers with active or past Graves' disease (GD). Current guidelines for the management of GD during pregnancy were based on studies conducted with first-generation thyroid-binding inhibitory immunoglobulin (TBII) assays.

OBJECTIVE

This retrospective study was conducted in order to specify the second-generation TBII threshold predictive of fetal and neonatal hyperthyroidism, and to identify other factors that may be helpful in predicting neonatal hyperthyroidism.

METHODS

We included 47 neonates born in the Lyon area to 42 mothers harboring measurable levels of TBII during pregnancy. TBII measurements were carried out in all mothers; bioassays were carried out in 20 cases.

RESULTS

Nine neonates were born with hyperthyroidism, including five with severe hyperthyroidism requiring treatment. Three neonates were born with hypothyroidism. All hyperthyroid neonates were born to mothers with TBII levels >5 IU/l in the second trimester (sensitivity, 100% and specificity, 43%). No mother with TSH receptor-stimulating antibodies (TSAb measured by bioassay) below 400% gave birth to a hyperthyroid neonate. Among mothers of hyperthyroid neonates, who required antithyroid drugs during pregnancy, none could stop treatment before delivery. Analysis of TBII evolution showed six unexpected cases of increasing TBII values during pregnancy.

CONCLUSION

Maternal TBII value over 5 IU/l indicates a risk of neonatal hyperthyroidism. Among these mothers, a TSAb measurement contributes to identify more specifically those who require a close fetal thyroid ultrasound follow-up. These results should be confirmed in a larger series.

Spontaneous abortion, stillbirth and hyperthyroidism: a danish population-based study

OBJECTIVES

Pregnancy loss in women suffering from hyperthyroidism has been described in case reports, but the risk of pregnancy loss caused by maternal hyperthyroidism in a population is unknown. We aimed to evaluate the association between maternal hyperthyroidism and pregnancy loss in a population-based cohort study.

STUDY DESIGN

All pregnancies in Denmark from 1997 to 2008 leading to hospital visits (n = 1,062,862) were identified in nationwide registers together with information on maternal hyperthyroidism for up to 2 years after the pregnancy [hospital diagnosis/prescription of antithyroid drug (ATD)]. The Cox proportional hazards model was used to estimate adjusted hazard ratio (aHR) with 95% confidence interval (CI) for spontaneous abortion (gestational age <22 weeks) and stillbirth (≥22 weeks), reference: no maternal thyroid dysfunction.

RESULTS

When maternal hyperthyroidism was diagnosed before/during the pregnancy (n = 5,229), spontaneous abortion occurred more often both in women treated before the pregnancy alone [aHR 1.28 (95% CI 1.18-1.40)] and in women treated with ATD in early pregnancy [1.18 (1.07-1.31)]. When maternal hyperthyroidism was diagnosed and treated for the first time in the 2-year period after the pregnancy (n = 2,361), there was a high risk that the pregnancy under study had terminated with a stillbirth [2.12 (1.30-3.47)].

CONCLUSIONS

Both early (spontaneous abortion) and late (stillbirth) pregnancy loss were more common in women suffering from hyperthyroidism. Inadequately treated hyperthyroidism in early pregnancy may have been involved in spontaneous abortion, and undetected high maternal thyroid hormone levels present in late pregnancy may have attributed to an increased risk of stillbirth.

Subclinical Thyroid Disorders: Clinical Significance and When to Treat?

Subclinical thyroid disorders are commonly encountered in the primary care setting. This article aims to review the latest evidence and guidelines pertaining to the management of subclinical hypo- and hyperthyroidism, in particular the important decision of when treatment should be considered.

Therapy of endocrine disease: antithyroid drug use in early pregnancy and birth defects: time windows of relative safety and high risk?

BACKGROUND

Antithyroid drugs (ATDs) may have teratogenic effects when used in early pregnancy.

OBJECTIVE

To review the association between the time period of ATD exposure in early pregnancy and the development of birth defects.

METHODS

We identified publications on birth defects after early pregnancy exposure to the ATDs methimazole (MMI; and its prodrug carbimazole (CMZ)) and propylthiouracil (PTU). Cases of birth defects after ATD treatment had been initiated or terminated within the first 10 weeks of pregnancy were identified and studied in detail.

RESULTS

A total of 92 publications were read in detail. Two recent large controlled studies showed ATD-associated birth defects in 2-3% of exposed children, and MMI/CMZ-associated defects were often severe. Out of the total number of publications, 17 included cases of birth defects with early pregnancy stop/start of ATD treatment, and these cases suggested that the high risk was confined to gestational weeks 6-10, which is the major period of organogenesis. Thus, the cases reported suggest that the risk of birth defects could be minimized if pregnant women terminate ATD intake before gestational week 6.

CONCLUSION

Both MMI and PTU use in early pregnancy may lead to birth defects in 2-3% of the exposed children. MMI-associated defects are often severe. Proposals are given on how to minimize the risk of birth defects in fertile women treated for hyperthyroidism with ATDs.