Cesarean Scar Pregnancies: Incidence and Factors Associated with Conversion to Surgery from Medical Management

To describe the incidence, management, and complications of cesarean scar pregnancy (CSP) and define risk factors for conversion from medical to surgical treatment of CSP.

Retrospective clinical study (Canadian Task Force classification II-3).

Tertiary medical center.

All patients who were admitted and treated for CSP between 2008 and 2016.

The cohort was divided according to management, and demographic, clinical, and sonographic data were collected. Rates of conversion were compared between groups, and risk factors necessitating conversion were sought.

Forty-six cases of CSP were identified. The incidence of CSP has increased from 0.05% to 0.09% of all deliveries. A regression model for absolute numbers of CSP predicted an additional 0.47 CSP each year (p = .03). The most common treatment modalities were systemic treatment with methotrexate (28.2%) and ultrasound-guided intrasac injection of KCl with systemic treatment of methotrexate (58.7%). The mean sac diameter (MSD) of cases that were converted was 11.2 mm larger than in cases that were not converted (p < .001). No patients with an MSD <10 mm or a trophoblastic mass <20 mm³ were converted to surgical management. Maximal levels of beta human chorionic gonadotropin (β-hCG) were significantly associated with the risk of conversion. Only 6.3% of patients with a β-hCG level <10,000 IU at presentation were converted from medical to surgical management. There was no significant association between fetal cardiac activity and conversion from medical to surgical management.

CSP has emerged as an important phenomenon in modern obstetrics and gynecology, and its frequency appears to be on the rise. The preferred method of treatment remains unclear; however, it is possible that a large MSD and trophoblastic mass at presentation should prompt surgical treatment.