A 32-year-old woman presents with fatigue, weight gain, and a serum TSH of 6.8 mIU/L (normal 0.4–4.0) with free T4 of 12 pmol/L (normal 12–22). Anti-TPO antibodies are strongly positive. She is trying to conceive. The most appropriate management is:
- A Observe and recheck TSH in 6 months without treatment
- B Start levothyroxine targeting TSH < 2.5 mIU/L ✓
- C Start propylthiouracil empirically
- D Radioiodine ablation therapy
Correct answer: B. Start levothyroxine targeting TSH < 2.5 mIU/L
Explanation
In a woman planning pregnancy, subclinical hypothyroidism (TSH > 4.0) with positive anti-TPO antibodies warrants levothyroxine therapy to target TSH < 2.5 mIU/L preconception, as per ATA guidelines. Untreated subclinical hypothyroidism in this context is associated with increased miscarriage and obstetric complications. Observation alone is inappropriate given conception plans and the positive antibody status.
Reference: Harrison's Principles of Internal Medicine, 21st ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.