Thyroid Disorders USMLE Step 1 Practice Question
A 29-year-old woman at 14 weeks gestation presents for prenatal care. She reports a 3-week history of palpitations, anxiety, and heat intolerance. Vital signs show heart rate 105 bpm and blood pressure 132/80 mmHg. Laboratory studies reveal TSH 0.1 mIU/L, free T4 2.8 ng/dL, and thyroid-stimulating immunoglobulin is positive. Which of the following is the appropriate first-line treatment?
Answer choices
- ABeta-blockade alone without antithyroid drugs
- BRadioactive iodine ablation
- CPropranolol for symptom control and propylthiouracil for antithyroid effectCorrect answer
- DLevothyroxine to suppress TSH and prevent fetal goiter
- EMethimazole monotherapy throughout pregnancy
- FIodine solution (Lugol's or saturated solution of potassium iodide) as monotherapy
See the full explanation
Get the correct-answer rationale, why each distractor is wrong, the underlying mechanism, and high-yield associations — plus adaptive practice that targets your weak areas — with a free MedBoardPRO account.