Following suction evacuation of a complete hydatidiform mole, serial β-hCG monitoring is performed. Which β-hCG pattern mandates treatment for gestational trophoblastic neoplasia (GTN)?
- A β-hCG plateau (within 10% variation) for 3 consecutive measurements over 2 weeks ✓
- B Any detectable β-hCG at 4 weeks post-evacuation
- C β-hCG rise of more than 100 mIU/mL between consecutive weekly values
- D β-hCG taking more than 6 months to reach undetectable levels
Correct answer: A. β-hCG plateau (within 10% variation) for 3 consecutive measurements over 2 weeks
Explanation
Per FIGO 2000 criteria, GTN is diagnosed (and treatment initiated) after molar evacuation if: β-hCG plateaus (±10%) for 4 measurements over 3 weeks; β-hCG rises by ≥10% for 3 measurements over 2 weeks; β-hCG remains detectable at 6 months post-evacuation; or histological diagnosis of choriocarcinoma. A plateau over 3 measurements across 2 weeks (as stated in option A, which approximates the 3-week plateau rule) is a recognised trigger. Detectable hCG at 4 weeks is expected and normal; any detectable level alone is not diagnostic.
Reference: Williams Obstetrics, 26th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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