A 23-year-old woman undergoes laparoscopic salpingostomy for a 3 cm right ampullary ectopic pregnancy. On postoperative day 10, her serum β-hCG has fallen from 2,800 IU/L to 1,950 IU/L. Which β-hCG threshold on day 10 best predicts the need for additional intervention due to persistent trophoblast?
- A β-hCG > 35% of the preoperative level ✓
- B β-hCG > 10% of the preoperative level
- C β-hCG > 50% of the preoperative level
- D β-hCG has not declined by at least 50% from day 0 to day 4
Correct answer: A. β-hCG > 35% of the preoperative level
Explanation
After conservative tubal surgery, persistent trophoblast occurs in 5-20% of cases. B day 10 β-hCG level exceeding 35% of the preoperative value is the most validated threshold for predicting failure and need for methotrexate or repeat surgery. B >10% threshold would over-treat many women who would otherwise resolve spontaneously. The day 0 to day 4 decline criterion applies to methotrexate monitoring, not postoperative surveillance.
Reference: High Risk Pregnancy: Management Options, 5th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.