Abstract: The retained products of conception (RPOC) is a presence of the intrauterine tissue related with pregnancy after the birth or termination of pregnancy. Ultrasonography is the principal method of RPOC diagnosis. The signals of blood flow are the main points of the ultrasonic diagnosis, with the characterizes of focal intrauterine membrane thickening, a intrauterine hyperechoic mass or a low-resistance arterial blood flow around the mass. The endometrial thickness and echo, as well as the ultrasound vascular grading, play an important role in the clinical diagnosis of RPOC, while hysteroscopy is the main method of the confirmed diagnosis. The differential diagnosis of this disease mainly includes arterial venous malformation and pregnancy trophoblastic disease, CT and MRI are helpful for the differential diagnosis. The treatment includes drug therapy and surgery. Mifepristone and misoprostol are of two common drugs for RPOC therapy. Surgical treatment has been gradually developed from the curettage under the guidance of ultrasound to the hysteroscopic focal clearance. With the advantages of high clearance rate and low incidence of complications, the hysteroscopic clearance is currently the main method of RPOC treatment.

Key words:  Retained products of conception, Ultrasonography, Vascular ultrasound, Hysteroscopy, Debridement