Endpoint
Clinical data from patients’ electronic medical records was reviewed retrospectively. The following variables were investigated: gestational weeks and mode of delivery, RPOC diameter at diagnosis, blood flow in RPOC, bleeding, infection, UAE, MROP, TCR, dilatation and curettage (D&C), hysterectomy, blood transfusion, the onset of heavy bleeding, date of RPOC disappearance, and serum hCG levels. We defined ”heavy bleeding” as bleeding accompanied by a change in vital signs; ”moderate bleeding” as normal menstrual blood loss; and ”light bleeding” as minor blood loss. Spontaneous resolution was defined as RPOC disappearance without removal of the placenta which confirmed by ultrasound or hysteroscopy.