Ectopic Pregnancy: Methotrexate Failure
A 30-year-old woman received single-dose methotrexate 50 mg/m² for a 3 cm unruptured tubal ectopic pregnancy one week ago. She now has worsening right iliac fossa pain, blood pressure 104/66 mm Hg, pulse 104 beats/min. Beta-hCG was 1000 mIU/mL on day 1, 1200 mIU/mL on day 4, and 2100 mIU/mL on day 7, with increasing pelvic free fluid. Which of the following is the most appropriate next step?
- A.Repeat beta-hCG measurement in one week
- B.Administer a second dose of methotrexate
- C.Proceed to laparoscopic surgical managementCorrect
- D.Start a multidose methotrexate regimen
Explanation
A beta-hCG that rises steeply between day 4 and day 7 after methotrexate, combined with worsening pain, tachycardia, a falling blood pressure and increasing free fluid, indicates failed medical therapy with impending or actual tubal rupture. The correct management is prompt surgery, usually laparoscopic salpingectomy, or salpingostomy when the contralateral tube is diseased and fertility preservation matters. Waiting a further week or giving more methotrexate risks catastrophic intraperitoneal haemorrhage, since the trophoblast is clearly still proliferating. Free fluid in the pouch of Douglas alongside pain and haemodynamic changes should be read as haemoperitoneum until proven otherwise. Laparoscopy is preferred over laparotomy in the stable or borderline patient because of less blood loss, shorter stay and quicker recovery; laparotomy is chosen when the patient is in shock or access is difficult. Anti-D immunoglobulin should be given to Rh-negative women. After salpingectomy no further hCG follow-up is required, whereas salpingostomy demands weekly hCG monitoring because of a 5% to 15% risk of persistent trophoblast. Isolated mild pain a few days after methotrexate without haemodynamic change can be observed, which is what distinguishes that scenario from this one.
Why each option
- A.
- Delaying a week in a patient with rising hCG, pain and free fluid risks rupture and major haemorrhage.
- B.
- A second dose may be considered for an asymptomatic plateau, but not when there are signs of rupture and a near doubling of hCG.
- C.
- Correct. Failed methotrexate with worsening pain, tachycardia and free fluid mandates surgical management.
- D.
- Adding a more toxic medical regimen does not address an actively bleeding or rupturing tubal pregnancy.
Reference: ACOG Practice Bulletin No. 193, Tubal Ectopic Pregnancy, reaffirmed 2022
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