A hemodynamically stable 7‑week pregnant woman with beta‑human chorionic gonadotropin 2000 IU/L, empty uterine cavity on ultrasound and a 3.5‑cm left tubal ectopic pregnancy, who has had bilateral tubal ligation, what is the most appropriate next step: salpingectomy, repeat investigations in 48 hours, methotrexate, or salpingostomy?

Management of Suspected Ectopic Pregnancy in a Hemodynamically Stable Patient with Prior Bilateral Tubal Ligation

Salpingectomy (Option A) is the definitive treatment for this patient with a confirmed 3.5 cm left adnexal mass, history of bilateral tubal ligation (indicating completed childbearing), and hemodynamic stability. 1

Rationale for Salpingectomy

This patient has a confirmed ectopic pregnancy based on the clinical picture: β-hCG of 2000 IU/L, empty uterus on ultrasound, and a 3.5 cm left adnexal mass at 7 weeks gestation. 2, 1 The absence of an intrauterine pregnancy when β-hCG is 2000 IU/L strongly suggests ectopic pregnancy, particularly with a visualized adnexal mass. 2

Why Salpingectomy Over Other Options:

• Prior bilateral tubal ligation indicates completed fertility, making tube preservation unnecessary and eliminating the primary rationale for conservative approaches 3, 4

• The 3.5 cm mass size is at the upper limit for methotrexate eligibility (relative contraindication ≥3.5 cm), making medical management suboptimal 1

• Salpingectomy avoids the 7% risk of persistent trophoblast that occurs with salpingotomy and the 8% risk of repeat ectopic pregnancy in the preserved tube 4

• Complete removal of the affected tube is the standard surgical treatment when fertility preservation is not desired 3

Why Other Options Are Inappropriate

Option B (Repeat Investigations in 48 Hours):

This patient does NOT have a pregnancy of unknown location (PUL). She has a confirmed adnexal mass measuring 3.5 cm, which represents a definitive finding requiring intervention. 1, 5 Delaying treatment risks tubal rupture and hemorrhage. 1 The American College of Emergency Physicians recommends against using β-hCG values alone to defer treatment when ultrasound shows definitive findings. 1

Option C (Methotrexate):

Methotrexate has relative contraindications in this case:

• Ectopic gestational sac ≥3.5 cm on ultrasound (this patient is at the threshold) 1
• Treatment failure rates of 15-23% with rupture rates of 0.5-9% 1
• The patient has already completed childbearing (bilateral tubal ligation), so the tube-sparing benefit is irrelevant 3, 4

Option D (Salpingostomy):

Salpingostomy is contraindicated because:

• The patient has had bilateral tubal ligation, indicating no desire for future fertility 3
• A large randomized controlled trial (n=446) demonstrated that salpingotomy offers no fertility advantage over salpingectomy even in women desiring pregnancy (fecundity rate ratio 1.06,95% CI 0.81-1.38) 4
• Salpingostomy carries a 7% risk of persistent trophoblast requiring additional methotrexate treatment 4
• Women themselves prefer avoiding repeat ectopic pregnancy over preserving fertility when given informed choice 6

Surgical Technique Considerations

The salpingectomy should include:

• Complete removal of the fallopian tube including the proximal isthmus but not the interstitial portion 3
• Careful preservation of the ovarian vascular supply 3
• Laparoscopic approach is appropriate given hemodynamic stability 3

Critical Safety Point

Hemodynamic stability must be continuously monitored. If the patient develops peritoneal signs, hypotension, or tachycardia before surgery, immediate surgical intervention becomes emergent rather than urgent. 1 The presence of lower abdominal pain with a 3.5 cm ectopic mass warrants expedited surgical consultation to prevent rupture. 1