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.