New ultrasound grading system for cesarean scar pregnancy and its implications for management strategies: An observational cohort study

Abstract

A cesarean section pregnancy (CSP) indicated the gestational sac (GS) implanted in the previous cesarean scar. The clinical manifestations of CSP present a wide range of variations, and the optimal management is yet to be defined. We retrospectively enrolled 109 patients with the diagnosis of CSP from our department and categorized them into four grades based on the ultrasound presentation. Grade I CSP indicated the GS embedded in less than one-half thickness of the lower anterior corpus; and grade II CSP represented the GS extended to more than one-half thickness of overlying myometrium. Grade III CSP implied the GS bulged out of the cesarean scar; and grade IV CSP denoted that GS became an amorphous tumor with rich vascularity at the cesarean scar. Seventy-eight women received surgery, and the complication rate was 14.1% (11/78). Linear regression analysis demonstrated a significant association between the invasiveness of the surgery and their ultrasound gradings. The mainstream operation for grade I CSP was transcervical resection, while the majority of grade III and IV patients required hysterotomy or hysterectomy. Another 31 women received chemotherapy with methotrexate as their initial treatment. The success rate for chemotherapy was 61.3%; the remaining patients required further surgery due to persistent CSP or heavy bleeding during or after chemotherapy. Fifteen patients (48.3%) receiving chemotherapy suffered from complications (mostly bleeding). Among them, 7 (22.6%) patients experienced bleeding of more than 1,000 mL, and 9 (29.0%) of these 31 patients required blood transfusions. Our novel ultrasound grading system for CSP may help to communicate between physicians, and determine the optimal surgical strategy. Chemotherapy with methotrexate for CSP is not satisfactory and is associated with a higher rate of complications.

Fig 1. The description of our new ultrasound grading system for CSP.

Grade I CSP represented the depth of CSP embedded in less than one-half thickness of the lower anterior corpus. Grade II CSP implied CSP occupied more than one-half thickness of the lower anterior corpus. In grade III CSP, the GS bulged out the overlying myometrium and uterine serosa. In grade IV CSP, the GS became an amorphous tumor with rich vascularity at the cesarean scar.

Fig 2. Outcome and complications in surgical patients with different grading of CSP (n = 78).

TCR: Transcervical resection by hysteroscopy; LSC: Laparoscopic hysterotomy; BT: Blood transfusion; BL: Blood loss; Laparotomy: hysterotomy via mini-laparotomy or conventional laparotomy; UAE: uterine artery embolization.

Fig 3. Outcome and complications of the patients receiving chemotherapy (n = 31).

Foley: uterine tamponade by Foley catheter. BT: blood transfusion; TCR: transcervical resection by hysteroscopy; Laparotomy: hysterotomy via mini-laparotomy or conventional laparotomy. UAE: uterine artery embolization. BL: blood loss.