What is the management approach for a suspected scar ectopic pregnancy identified by the crossover sign?

Management of Cesarean Scar Ectopic Pregnancy with Crossover Sign

When a cesarean scar ectopic pregnancy is identified by ultrasound (including the crossover sign), immediate intervention is required—expectant management should be avoided due to high risk of uterine rupture and life-threatening hemorrhage. 1

Immediate Diagnostic Confirmation

The crossover sign indicates that the gestational sac crosses over the anterior uterine wall at the level of the cesarean scar, confirming implantation within the myometrium and fibrous scar tissue rather than in the uterine cavity. 2 This ultrasound finding, combined with absence of an intrauterine pregnancy and positive β-hCG, establishes the diagnosis of cesarean scar ectopic pregnancy (CSEP). 3

Treatment Algorithm

First-Line Surgical Approaches (Preferred)

Operative resection via transvaginal or laparoscopic approach should be considered as primary treatment, as these methods remove both the pregnancy and scar tissue to reduce morbidity and promote future fertility. 4, 1

• Laparoscopic excision allows direct visualization, removal of the gestational sac with surrounding myometrium, and repair of the uterine defect 5
• Transvaginal surgical removal is an alternative minimally invasive option when feasible 4, 1
• Sharp curettage alone must be avoided due to high risk of hemorrhage and incomplete removal 1

Alternative: Ultrasound-Guided Aspiration

Ultrasound-guided uterine aspiration can be considered as a surgical management option, though it may require additional interventions. 1

Medical Management Option

Intragestational methotrexate (injected directly into the gestational sac under ultrasound guidance) can be used, with or without other treatment modalities. 6, 1

• Local injection of methotrexate ± KCl under ultrasound guidance has shown success in case reports 6
• Systemic methotrexate alone should NOT be used as it has insufficient efficacy for CSEP 1
• Medical management often requires additional surgical intervention for complete resolution 4

Combination Approaches

Uterine artery embolization combined with other modalities may be considered, though evidence is limited. 4

Critical Management Principles

• Expectant management is contraindicated due to substantial risk of uterine rupture, massive hemorrhage, and maternal mortality 1
• Hemodynamically unstable patients require immediate surgical intervention, potentially including hysterectomy if hemorrhage is uncontrolled 5
• Early diagnosis and intervention prevent life-threatening complications and preserve fertility 2, 5

Common Pitfalls to Avoid

• Misdiagnosing as intrauterine pregnancy or threatened abortion, leading to inappropriate curettage and catastrophic hemorrhage 4
• Attempting sharp curettage alone without recognizing the diagnosis, which can cause massive bleeding 1
• Using systemic methotrexate as sole therapy, which has inadequate efficacy 1
• Delaying treatment in hemodynamically stable patients—this is NOT a pregnancy of unknown location requiring serial β-hCG monitoring 7

Post-Treatment Counseling

Patients must be counseled about risks of future pregnancy and offered effective contraception, including long-acting reversible contraception or permanent sterilization. 1 The risk of recurrent cesarean scar pregnancy in subsequent pregnancies is significant. 2

If Patient Declines Treatment

In rare cases where patients decline intervention and continue the pregnancy, repeated cesarean delivery between 34 0/7 and 35 6/7 weeks of gestation is recommended, with preparation for massive hemorrhage and potential hysterectomy. 1 However, patients must understand the extremely high risk of severe morbidity including uterine rupture and life-threatening bleeding. 1, 5