Scarred for life: a review of cesarean section scar pregnancy and potential pitfalls in diagnosis

Cesarean section scar pregnancy (CSSP) is defined as abnormal implantation of a gestational sac on or in a previous cesarean section scar. There is an increasing incidence of detection of CSSP, likely in part due to the growing rates of cesarean deliveries and the improved rates of detection with advancing ultrasound technology. Diagnosis of CSSP is critical due to the potentially life-threatening complications to the mother if left untreated. Pelvic ultrasound is the imaging modality of choice in the initial evaluation of suspected CSSP, with MRI potentially useful if ultrasound findings are equivocal, or if confirmation is requested prior to definitive intervention. Early and accurate diagnosis of CSSP allows for prompt management to avoid severe complications and the potential to preserve the uterus and future fertility. A combination of medical and surgical treatment strategies may be needed with specific therapy tailored to each patient. Follow-up after treatment should include serial beta-hCG levels and possible repeat imaging if there is clinical concern for complications or treatment failure. This article will provide a comprehensive review of this uncommon but important phenomenon, detailing the pathophysiology and types of CSSP, imaging presentations, potential pitfalls in diagnosis, and management options.