What is the best management for a pregnant patient with hyperthyroidism and a cold nodule?

From the Guidelines

The best management for a pregnant patient with hyperthyroidism and a cold nodule is to use antithyroid medications, specifically propylthiouracil (PTU) during the first trimester and methimazole for the second and third trimesters, while evaluating the cold nodule with fine needle aspiration to rule out malignancy. This approach is based on the most recent and highest quality evidence, which prioritizes the safety of both the mother and the fetus. The patient's condition should be managed with careful medication selection, monitoring of TSH and free T4 levels, and short-term use of beta-blockers for symptom control. Some key points to consider in the management of this patient include:

• The use of PTU during the first trimester at the lowest effective dose (typically 100-300 mg/day divided into three doses) to minimize the risk of birth defects 1.
• Switching to methimazole (10-30 mg/day) for the second and third trimesters due to lower risk of birth defects 1.
• Evaluating the cold nodule with fine needle aspiration to rule out malignancy, as pregnancy does not preclude this diagnostic procedure.
• Monitoring TSH and free T4 levels every 2-4 weeks initially, then monthly once stable, aiming for free T4 in the upper normal range.
• Using beta-blockers (preferably propranolol 10-40 mg three to four times daily) short-term for symptom control.
• Considering surgery (thyroidectomy) only if there is suspicion of malignancy, severe drug reactions, or inability to control hyperthyroidism medically, ideally performed during the second trimester.
• Avoiding radioactive iodine during pregnancy due to its potential harm to the fetus 1. It is essential to balance maternal disease control with fetal safety, as untreated hyperthyroidism poses significant risks to both mother and fetus, including preeclampsia, preterm birth, and fetal growth restriction. The management of hyperthyroidism in pregnancy requires a multidisciplinary approach, and the patient should be closely monitored by a team of healthcare professionals, including an obstetrician, endocrinologist, and radiologist. By following this approach, the patient can receive the best possible care, and the risks associated with hyperthyroidism and pregnancy can be minimized. The cold nodule should be evaluated and managed according to the latest guidelines, which recommend fine needle aspiration for nodules with suspicious features 1. Overall, the management of a pregnant patient with hyperthyroidism and a cold nodule requires careful consideration of the potential risks and benefits of different treatment options, and a multidisciplinary approach is essential to ensure the best possible outcomes for both the mother and the fetus.

From the FDA Drug Label

Pregnancy Category D If methimazole is used during the first trimester of pregnancy or if the patient becomes pregnant while taking this drug, the patient should be warned of the potential hazard to the fetus In pregnant women with untreated or inadequately treated Graves’ disease, there is an increased risk of adverse events of maternal heart failure, spontaneous abortion, preterm birth, stillbirth and fetal or neonatal hyperthyroidism Because methimazole crosses placental membranes and can induce goiter and cretinism in the developing fetus, hyperthyroidism should be closely monitored in pregnant women and treatment adjusted such that a sufficient, but not excessive, dose be given during pregnancy Due to the rare occurrence of congenital malformations associated with methimazole use, it may be appropriate to use an alternative anti-thyroid medication in pregnant women requiring treatment for hyperthyroidism particularly in the first trimester of pregnancy during organogenesis.

The best management for a pregnant patient with hyperthyroidism and a cold nodule is not explicitly stated in the provided drug label. However, considering the patient is 14 weeks pregnant, which is in the second trimester, and the presence of a cold nodule, the management should focus on controlling the hyperthyroidism while minimizing risks to the fetus.

• Antithyroid drugs like methimazole can be used, but the dose should be adjusted to avoid excessive levels.
• Surgical options such as total thyroidectomy or excision of the cold nodule may be considered, but the decision should be made on a case-by-case basis, taking into account the risks and benefits.
• Radio-iodine is contraindicated in pregnancy due to the risk of ablating the fetal thyroid gland.
• External beam radiation is not a standard treatment for hyperthyroidism and is not recommended in pregnancy. Given the information provided and the need for careful management of hyperthyroidism in pregnancy, the choice between a. Total thyroidectomy and b. Excision of the cold nodule then antithyroid drugs would depend on the specific clinical circumstances and the expertise of the managing team 2.

From the Research

Management of Hyperthyroidism in Pregnancy

The management of hyperthyroidism in pregnancy is crucial to prevent maternal and fetal complications.

• The primary goal is to achieve a euthyroid state, and antithyroid drugs are the main therapeutic option administered in pregnant women 3.
• Radioactive iodine therapy is contraindicated during pregnancy, and thyroidectomy should be limited to severe non-responsive thyroid dysfunction pregnant patients 3.
• The choice of antithyroid drug depends on the trimester of pregnancy, with propylthiouracil (PTU) preferred in the first trimester due to its lower teratogenic risk compared to methimazole (MMZ) 4, 5.
• However, PTU may cause liver injury, and MMZ may cause congenital malformations, highlighting the need for careful monitoring and management 4, 5.

Cold Nodule Management

In the presence of a cold nodule, the management approach may vary.

• Excision of the cold nodule may be considered, but it is essential to weigh the risks and benefits of surgery during pregnancy 6.
• Antithyroid drugs may be used to manage hyperthyroidism, and the cold nodule can be monitored concurrently 6, 7.

Best Management Option

Considering the patient's presentation at 14 weeks of gestation with hyperthyroidism and a cold nodule, the best management option would be:

• Excision of the cold nodule is not the primary concern at this stage, and antithyroid drugs can be used to manage hyperthyroidism 6, 7.
• Given the patient's gestational age, propylthiouracil (PTU) may be preferred due to its lower teratogenic risk compared to methimazole (MMZ) 4, 5.
• Therefore, the best management option would be to use antithyroid drugs, specifically PTU, to manage hyperthyroidism, and monitor the cold nodule concurrently.
• The correct answer is: b. Excision of the cold nodule then antithyroid drugs.