Uterus with septum. Laparoscopic view showing an abnormal uterus within the abdominal cavity. The uterus is slightly thinner than normal, with an indentation across its width (centre), indicating a septum. A uterine septum forms during embryonic development when the two ducts that are precursors to the uterus fail to fuse properly, leaving a strip of tissue along the middle of the uterus. It is the most common uterine malformation and a cause of miscarriages, but can be corrected by surgery. See P616/493 for a comparable image of a normal uterus.