Neonatal Screening for Hyperthyroidism proof of concept

Context Early treatment is essential to avoid the cardiac complication of Neonatal hyperthyroidism (NH). Our results have direct implications for clinical care. Objective NH can cause potentially fatal neonatal thyrotoxicosis. Here, we evaluated the feasibility of neonatal hyperthyroidism screening using the thyroid-stimulating hormone value in dried blood collected routinely on filter paper on the third postnatal day of life for congenital hypothyroidism screening. Design Retrospective case-control Methods Cases were identified using data from our previously published study of 280,000 infants born in ten maternity units in France in 2007-2014. Controls were identified among the 1,362,564 infants born in the Ile-de-France region during the same period. Results A screening thyroid-stimulating hormone level below 0.18 mIU/L on the third postnatal day had 71% (95% confidence interval [95%CI], 44%–90%) sensitivity, 99% (95%CI, 99%–100%) specificity, 81% (95%CI, 74%–86%) positive predictive value, and 98% (95%CI, 97%–99%) negative predictive value for detecting severe NH. By univariate regression analysis, the screening thyroid-stimulating hormone value was the strongest predictor of NH (p<0.00001), with an area under the receiver-operating characteristics curve of 0.98 (95%CI, 0.95–1.0). Expected frequencies were not significantly different from observed frequencies (Hosmer-Lemeshow test, p=0.99). Conclusions The screening thyroid-stimulating hormone test can be used to detect severe NH, the optimal cut-off being 0.18 mIU/L. The additional cost compared to screening for congenital hypothyroidism only would be small. Infants with neonatal hyperthyroidism would benefit from an earlier diagnosis with treatment initiation at the pre-symptomatic stage in many cases, ensuring optimal outcomes.

APPROACH TO THE PATIENT Fetal and neonatal thyroid dysfunction

Fetal and neonatal dysfunctions include rare serious disorders involving abnormal thyroid function during the second half of gestation, which may persist throughout life, as for most congenital thyroid disorders, or be transient, resolving in the first few weeks of life, as in autoimmune hyperthyroidism or hypothyroidism and some cases of congenital hypothyroidism (CH) with the thyroid gland in situ. Primary CH is diagnosed by neonatal screening, which has been implemented for 40 years in developed countries and should be introduced worldwide, as early treatment prevents irreversible neurodevelopmental delay.Central CH is a rarer entity occurring mostly in association with multiple pituitary hormone deficiencies. Other rare disorders impair the action of thyroid hormones. Neonatal Grave’s disease (GD) results from the passage of thyrotropin receptor antibodies (TRAb) across the placenta, from mother to fetus. It may affect the fetuses and neonates of mothers with a history of current or past GD, but hyperthyroidism develops only in those with high levels of stimulatory TRAb activity. The presence of antibodies predominantly blocking TSH receptors may result in transient hypothyroidism, possibly followed by neonatal hyperthyroidism, depending on the balance between the antibodies present. Antithyroid drugs taken by the mother cross the placenta, treating potential fetal hyperthyroidism,but they may also cause transient fetal and neonatal hypothyroidism. Early diagnosis and treatment are key to optimizing the child’s prognosis. This review focuses on the diagnosis and management of these patients during the fetal and neonatal periods. It includes the description of a case of fetal and neonatal autoimmune hyperthyroidism.

Hyperthyroidism in Pregnancy: The Delicate Balance between too Much or too Little Antithyroid Drug

Overt hyperthyroidism (HT) during pregnancy is associated with a risk of maternal–fetal complications. Antithyroid drugs (ATD) have a potential risk for teratogenic effects and fetal–neonatal hypothyroidism. This study evaluated ATD treatment and thyroid function control during pregnancy, and pregnancy outcome in women with HT. Patients and methods: A retrospective analysis of 36 single fetus pregnancies in 29 consecutive women (median age 30.3 ± 4.7 years) with HT diagnosed before or during pregnancy; a control group of 39 healthy euthyroid pregnant women was used. Results: Twenty-six women had Graves’ disease (GD, 33 pregnancies), 1 had a hyperfunctioning autonomous nodule, and 2 had gestational transient thyrotoxicosis (GTT). Methimazole (MMI) was administered in 22 pregnancies (78.5%), Propylthiouracil (PTU) in 2 (7.1%), switch from MMI to PTU in 4 (14.2%), no treatment in 8 pregnancies (3 with subclinical HT, 5 euthyroid with previous GD remission before conception). In the 8 pregnancies of GD patients diagnosed during gestation or shortly before (<6 weeks), i.e., with fetal exposure to uncontrolled HT, there was 1 spontaneous abortion at 5 weeks (3.4% of all ATD-treated pregnancies), and 1 premature delivery at 32 weeks with neonatal death in 24 h (3.4%); 1 child had neonatal hyperthyroidism (3.3% of live children in GD women) and a small atrial sept defect (4% of live children in ATD treated women). In women treated more than 6 months until conception (20 pregnancies): (a) median ATD doses were lower than those in women diagnosed shortly before or during pregnancy; (b) ATD was withdrawn in 40% of pregnancies in trimester (T)1, all on MMI < 10 mg/day (relapse in 14.2%), and in up to 55% in T3; (c) TSH level was below normal in 37%, 35% and 22% of pregnancies in T1, T2 and T3 respectively; FT4 was increased in 5.8% (T1) and subnormal in 11.75% in T2 and T3; (d) no fetal birth defects were recorded; one fetal death due to a true umbilical cord knot was registered. Mean birth weight was similar in both ATD-treated and control groups. Hyperthyroidism relapsed postpartum in 83% of GD patients (at median 3 ± 2.6 months). Conclusion: In hyperthyroid women with long-term ATD treatment before conception, drugs could be withdrawn in T1 in 40% of them, the thyroid function control was better, and pregnancy and fetal complications were rarer, compared to women diagnosed during pregnancy. Frequent serum TSH and FT4 monitoring is needed to maintain optimal thyroid function during pregnancy.

Hyperthyroidism in Pregnancy: the Delicate Balance between too Much or too Little Antithyroid Drug

Overt hyperthyroidism during pregnancy is associated with risk of maternal-fetal complications. The antithyroid drugs (ATD) have a potential risk for teratogenic effects and fetal&ndash;neonatal hy-pothyroidism. This study evaluated ATD treatment and thyroid function control during preg-nancy, and pregnancy outcome in women with hyperthyroidism. Patients and methods: retro-spective analysis of 36 single fetus pregnancies in 29 consecutive women (median age 30.3 &plusmn; 4.7 years) with hyperthyroidism diagnosed before or during pregnancy; a control group of 39 healthy euthyroid pregnant women was used. Results: 26 women had Graves&rsquo; disease (GD, 33 pregnan-cies), 1 had a hyperfunctioning autonomous nodule, 2 had gestational transient thyrotoxicosis (GTT). Methimazole (MMI) was administered in 22 pregnancies (78.5%), Propylthiouracil (PTU) in 2 (7.1%), switch from MMI to PTU in 4 (14.2%), no treatment in 8 pregnancies (3 with subclinical hyperthyroidism, 5 euthyroid with previous GD remission before conception). One spontaneous abortion at 5 weeks (3.4% of pregnancies) and 1 premature delivery at 32 weeks with perinatal death in 24h (3.4%) were recorded in 2 of the 8 pregnancies of GD patients diagnosed shortly before (&lt; 6 weeks) or during gestation. In women treated more than 6 months until conception (20 pregnancies): a) median ATD doses were lower than those in women diagnosed shortly before or during pregnancy; b) ATD was withdrawn in 40% of pregnancies in trimester (T) I, all on MMI &lt; 10 mg/day (relapse in 14.2%), and in up to 55% in TIII; c) TSH level was below normal in 37%, 35% and 22% of pregnancies in T I, II and III respectively; FT4 was increased in 5.8% (T I) and sub-normal in 11.75% in TII and III; d) one fetal death due to a true umbilical cord knot was recorded. Hyperthyroidism relapsed postpartum in 83% of GD patients (at median 3 &plusmn; 2.6 months). One child had neonatal hyperthyroidism (3.3% of live children in GD women) and a small atrial sept defect (4% of live children in ATD treated women). Mean birth weight did not differ from that of the control group. Conclusion. In hyperthyroid women with long-term ATD control before con-ception, drugs could be withdrawn in TI in a third of them, and fetal complications were rare. Frequent serum TSH and FT4 monitoring is needed in order to maintain optimal thyroid function during pregnancy.

Prevalence and course of thyroid dysfunction in neonates at high risk of Graves’ disease or with non-autoimmune hyperthyroidism

Objective Neonatal hyperthyroidism may be caused by a permanent non-autoimmune genetic disorder or, more frequently, by maternally transmitted high serum TRAb levels. Variable thyroid dysfunction may be observed in this second context. We aimed to evaluate the prevalence of neonatal non-autoimmune hyperthyroidism and of the different types of thyroid function in neonates with a high risk of hyperthyroidism due to maternal Graves’ disease (GD). Design and methods This observational cohort study included all neonates identified in the database of a single academic pediatric care center, over a period of 13 years, as having non-autoimmune hyperthyroidism or an autoimmune disorder with high TRAb levels (above 6 IU/L) transmitted by their mothers. Patients were classified as having neonatal hyperthyroidism, hypothyroidism, or euthyroidism with a permanent or transient disorder. Results Two of the 34 consecutive neonates selected (6%) had permanent non-autoimmune hyperthyroidism due to germline (n = 1) or somatic (n = 1) mutations of the TSH receptor gene. The patients with high serum TRAb levels at birth had transient hyperthyroidism (n = 23), hypothyroidism (primary n = 2, central n = 3) or persistent euthyroidism (n = 4). Conclusion These original findings highlight the need for careful and appropriate monitoring of thyroid function in the long term, not only for the rare patients with non-autoimmune neonatal hyperthyroidism, but also for repeat monitoring during the first month of life in neonates with maternally transmitted high TRAb levels, to ensure the early identification of thyrotoxicosis in more than two thirds of cases and to detect primary or central hypothyroidism, thereby potentially decreasing associated morbidity.

Pregnancy and Graves’ Disease

Graves’ disease (GD) is one of the most common autoimmune conditions in women of reproductive age. The disorder is characterized by the presence of pathogenic immunoglobulins that bind the TSH receptors (TRAbs) and stimulate the production of thyroid hormones leading to hyperthyroidism (the occurrence of inhibiting or neutral antibodies being rare). Affected individuals can be treated by radioiodine therapy, surgical removal of the gland or by antithyroid drugs (ATDs). Thyroid stimulating immunoglobulins may persist for years after medical treatment, radioiodine therapy or surgical removal of the gland in those affected by GD and during pregnancy can cross the placenta and can act on the fetal thyroid gland resulting in the development of fetal and neonatal hyperthyroidism and sometimes to goiter. Antithyroid drugs used during pregnancy can also cross the placenta and may be teratogenic and act on the fetal thyroid gland, leading to fetal and neonatal hypothyroidism and goiter. This chapter will discuss specific aspects of GD during pregnancy and postpartum focusing on fetal and neonatal consequences related to this disorder.

SUN-517 Methimazole-Induced Neutropenia in Premature Twins with Graves’ Disease

Introduction: Neonatal Graves’ disease (NGD) occurs in approximately 1-5% of infants born to women with Graves’ disease. It is caused by trans-placental crossing of thyroid stimulating immunoglobulin (TSI) antibodies during third trimester. Hyperthyroidism during pregnancy can lead to craniosynostosis, goiter, premature bone maturation, developmental delay or even heart failure in the neonate. Neonatal Hyperthyroidism is usually transient and resolves in few weeks. Treatment consists of beta blockers and Methimazole. Studies in adults recommend discontinuing of Methimazole if patients develop neutropenia. However due to lack of alternatives, we present a case of continued use of Methimazole with neutropenia in newborn twins. Case Report: 33 weeks gestational age mono-chorionic/di-amniotic twins born to a 34-year-old woman with poorly controlled hyperthyroidism. Mother diagnosed with Graves’ disease during 2nd trimester with poor control throughout pregnancy. At the time of delivery, maternal TSH was &lt;0.005uIU/mL(0.358-3.74uIU/mL) and FT4 2.18ng/dL(0.76-1.46ng/dL). Antenatal ultrasound at 32 weeks showed homogeneous enlargement of fetal thyroid glands with increased vascularity in both twins. Babies found to have diffuse goiter and exophthalmos at birth. Thyroid tests remained normal for first 3 days of life. By day 3, babies labs showed TSH &lt;0.005uIU/mL, FT4 -8 ug/dL and TSI &gt;700%. Baseline CBC showed ANC of 4.95K/mm3. Babies were started on Methimazole 0.5mg/kg/day and Propranolol 2mg/kg/day. TFTs fluctuated throughout their stay in NICU and they developed neutropenia with ANC 1.23K/mm3 on day 20 of life. Methimazole was initially discontinued then restarted at 0.25 mg/kg/day 3 days later. There is no recommended protocol for restarting Methimazole. Further follow up showed persistent neutropenia despite multiple dose adjustments in Methimazole, including dosing every other day. ANC was maintained around 800-1100K/mm3. At age 2 months, Methimazole was discontinued completely after TSI antibodies decreased to 400%. ANC remained low until 6 months of life, even after discontinuing Methimazole. Both babies ultimately developed central hypothyroidism and were started on l-thyroxine. Discussion: NGD can range anywhere from transient hyperthyroidism to persistent central hypothyroidism. Early diagnosis and treatment is crucial to prevent significant morbidity and mortality. Methimazole is the only approved treatment at this age, and management of Methimazole-induced neutropenia has not been established. Adult studies recommend discontinuing Methimazole in context of neutropenia; we took an approach of decreasing dose gradually. Further studies are needed to establish step-wise approach in managing Methimazole-induced neutropenia.

SAT-075 Pulmonary Hypertension in a Patient with Neonatal Graves Disease

INTRODUCTION Neonatal hyperthyroidism is a transient disorder seen in neonates born to mothers with current or past history of Graves’ disease. We present a rare case of a Neonatal Graves’ disease with pulmonary hypertension (PH) which completely resolved with treatment of hyperthyroidism. CLINICAL CASE Baby B was a 3200 g term male born to a 40-year-old hypothyroid mother. He was prenatally diagnosed with Trisomy 21 and coarctation of the aorta (CoA). He developed respiratory distress soon after birth and was admitted to the NICU. His echocardiogram (echo) showed a large patent ductus arteriosus (PDA) and increased tortuosity of juxtaductal aorta with no significant gradient. Near-systemic pulmonary artery pressure was noted in the absence of any evidence of left heart failure. Cardiology determined his CoA to be hemodynamically insignificant and not the cause of his PH. Successive trials of 100% FiO2, Nitric Oxide (NO), and Sildenafil resulted in only minimal improvement of his PH. Thyroid function tests (TFT) obtained on day of life (DOL) 8 showed serum TSH of 0.01 uIU/ml [0.87 - 6.43] and FT4 of 3.5 ng/dl [0.9 - 1.5]. Further interaction with the mother revealed that she had a history of Graves’ disease treated with radioactive iodine (RAI) and resultant hypothyroidism. Baby B’s TSH receptor antibody (TRAb) and thyroid stimulating immunoglobulin levels were elevated at 7.38 IU/l [0-1.75] and 3.38 IU/l [0-0.55], respectively. He was thus diagnosed with Neonatal Graves’ disease and was started on Methimazole (MTZ) 1 mg/kg/day on DOL 8. Subsequently, potassium iodide was added. FT4 showed gradual normalization by DOL 15. Beta blockers were not added due to absence of hypertension or significant tachycardia. Serial echo showed improvement of PH, consistent with the decline in FT4 levels. Sildenafil and FiO2 were slowly weaned and discontinued by DOL 30. MTZ was then tapered and discontinued. A final echo showed complete resolution of PH, unobstructed aortic arch and persistent PDA. DISCUSSION Neonatal hyperthyroidism occurs due to transplacental transfer of TRAb from mother to fetus, stimulating the fetal thyroid to make excessive thyroid hormones. Risk correlates with TRAb titers in the mother. Our patient had pulmonary hypertension which did not resolve with FiO2, NO and Sildenafil. However, it showed complete resolution with normalization of FT4 levels by antithyroid drugs. Hyperthyroidism commonly presents with systemic HTN, but we found 3 neonatal cases in the literature presenting with PH that resolved with treatment of hyperthyroidism. The mechanism is unclear, but hypotheses include increased clearance of pulmonary vasodilators and decreased clearance of pulmonary vasoconstrictor and decreased surfactant production/function(1). REFERENCES 1) Oden J, Cheifetz IM. Neonatal thyrotoxicosis and persistent PH necessitating extracorporeal life support. Pediatrics 2005-115: e105-8.

Macular Rash, Thrombocytopenia, and Hyperbilirubinemia in a Preterm Infant

Neonatal hyperthyroidism is usually caused by the passage of maternal thyroid receptor antibodies. This relatively rare condition has various manifestations including cholestasis, prematurity, and cardiomegaly. We present a case of a preterm infant with neonatal Graves’ disease who presented with cholestasis, cardiomegaly, and a macularpapular rash that was thought to be suspicious for congenital infection. This case has been reported to illustrate lessons learnt for early identification of a neonate with Graves’ disease in order to expedite treatment.