Discussion of Septate uterus
- Septate uterus is the most common müllerian duct anomaly (composes approximately 55% of müllerian duct anomalies)
- Results from partial or complete failure of resorption of the uterovaginal septum after fusion of the paramesonephric ducts.
- The septate uterus is also associated with the worst obstetric outcome of the müllerian duct anomalies.
- Reproductive outcome has been shown to improve after resection of the septum, with reported decreases in the spontaneous abortion rate from 88% to 5.9% after hysteroscopic metroplasty.
- The septum, which arises in the midline fundus, is considered to be complete when it extends to the external cervical os.
- The external uterine contour may be convex, flat, or mildly (<1.0-cm) concave.
- The configuration of the external uterine contour is crucial for the differentiation of a septate from a bicornuate uterus, because widely different clinical and interventional approaches are assigned to each anomaly.
- A septate uterus is often treated with hysteroscopic resection of the septum.
- Bicornuate uteri rarely necessitate surgical intervention.
 Imaging Findings for Septate uterus
- Accuracy of alone is only 55% for differentiation of septate from bicornuate uteri.
- An angle of less than 75° between the uterine horns is suggestive of a septate uterus, and an angle of more than 105° is more consistent with bicornuate uteri.
- Unfortunately, the majority of angles of divergence between the horns fall within this range, and considerable overlap between the two anomalies is noted.
- At US, the echogenic endometrial cavities are separated at the fundus by the intermediate echogenicity of the myometrium in all partial septa and within the fundal segments of complete septa.
- The external uterine contour must demonstrate a convex, flat, or mildly concave configuration and may best be appreciated on transverse images of the uterus.
- On MR images, the septate uterus is generally normal in size and each endometrial cavity appears smaller than the configuration of a normal cavity.
- In both partial and complete septa, the signal intensity within the fundal segment of the septum is isointense with the adjacent myometrium.
- Mullerian duct anomalies classification system
- Arcuate uterus
- Bicornuate uterus
- Unicornuate uterus
- Uterus didelphys
 External Links
 References for Septate uterus
- Robert N. Troiano, and Shirley M. McCarthy. Müllerian Duct Anomalies: Imaging and Clinical Issues. Radiology 2004 233: 19-34.