It is considered the commonst uterine anomaly (accounts for ~ 55% of such anomalies) and is the most common anomaly associated with reproductive failure (in 67%.).
It is considered a type of uterine duplicational anomaly and results from partial or complete failure of resorption of the uterovaginal septum after fusion of the para-mesonephric ducts. The septum is usually fibrous but can also have varying muscular components.
The external uterine contour may be convex, flat, or mildly (< 1cm) concave.
- complete septum extends to internal os - septate uterus
- partial septum involves endometrial canal but not cervix - sub-septate uterus
- septum extends into the vagina - septate uterus and vagina
The septum, which arises in the midline fundus, is considered to be complete when it extends to the external cervical os.
As with other uterine anomalies, concurrent renal anomalies may be associated
- convex / flat / minimally indented external fundal contour
- acute angle of < 75% between uterine cavities
- endometrial canals are completely separated by tissue iso-echoic to myometrium with extension into endocervical canal
On ultrasound, 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 (ideally no more than 1cm) configuration and may best be appreciated on transverse images of the uterus.
May show vascularity in the septum in 70% of cases : and if present may be associated with a higher rate of obstetric complications 8
Fluoroscopy - Hysterosalpingogram
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.
MRI is considered the imaging modality choice in modern radiological practice.
On MR images, the septate uterus is generally normal in size and each endometrial cavity appears smaller than the configuration of a normal cavity.
The septum may be composed of fibrous tissue (low T2 signal intensity), myometrium (intermediate signal) or both 2.
- 90% miscarriage rate
- a septate uterus is associated with the worst obstetric outcome of the Müllerian duct anomalies.
- patients with septate uteri usually do not have difficulty
conceiving, but the pregnancies frequently end in abortion or premature birth.
Treatment and prognosis
The distinction between septate uterus and bicornuate uterus has important management implications. In septate uterus, but not in bicornuate uterus, the septum can be shaved off during hysteroscopy (metroplasty) to form a single uterine cavity without perforating the uterus 4.
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.
Considerations a hysterosalpingogram include
- bicornuate uterus: 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.
On ultrasound images in the certain planes, also consider
- thick intra-uterine adhesion band
Abdominal and pelvic anatomy
- skeleton of the abdomen and pelvis
- muscles of the abdomen and pelvis
- anterior abdominal wall (surface anatomy)
- posterior abdominal wall
- pelvic floor
- spaces of the abdomen and pelvis
- posterior abdominal wall
- peritoneal ligaments
- right supramesocolic space
- lesser supramesocolic space
- supramesocolic space
- inguinal canal (mnemonic)
- scrotal sac
- pelvic cavity
- abdominal and pelvic viscera
- gastrointestinal tract
- biliary system
- endocrine system
- renal pelvis
- renal sinus
- avascular plane of Brodel
- urinary bladder
- male reproductive system
female reproductive system
- uterine tubes
- variant anatomy
- blood supply of the abdomen and pelvis
- inferior phrenic artery
- coeliac artery
- superior mesenteric artery
- middle suprarenal artery
- renal artery (variant anatomy)
- gondal artery (ovarian artery | testicular artery)
- inferior mesenteric artery
common iliac artery
- external iliac artery
- internal iliac artery (mnemonic)
- abdominal aorta
- portal venous system
inferior vena cava
- hepatic vein confluence
- renal vein (variants)
- common iliac vein
- variant caval anatomy
- inferior vena cava
- innvervation of the abdomen and pelvis
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- 2. Saleem SN. MR imaging diagnosis of uterovaginal anomalies: current state of the art. Radiographics. 23 (5): e13. doi:10.1148/rg.e13 - Pubmed citation
- 3. Troiano RN, Mccarthy SM. Mullerian duct anomalies: imaging and clinical issues. Radiology. 2004;233 (1): 19-34. doi:10.1148/radiol.2331020777 - Pubmed citation
- 4. Chaudhry S. AJR Teaching File: infertility in a young woman. AJR Am J Roentgenol. 2007;189 (3): S11-2. doi:10.2214/AJR.07.7019 - Pubmed citation
- 5. Imaoka I, Wada A, Matsuo M et-al. MR imaging of disorders associated with female infertility: use in diagnosis, treatment, and management. Radiographics. 23 (6): 1401-21. doi:10.1148/rg.236025115 - Pubmed citation
- 6. Alborzi S, Dehbashi S, Parsanezhad ME. Differential diagnosis of septate and bicornuate uterus by sonohysterography eliminates the need for laparoscopy. Fertil. Steril. 2002;78 (1): 176-8. Fertil. Steril. (link) - Pubmed citation
- 7. Fedele L, Dorta M, Brioschi D et-al. Pregnancies in septate uteri: outcome in relation to site of uterine implantation as determined by sonography. AJR Am J Roentgenol. 1989;152 (4): 781-4. AJR Am J Roentgenol (abstract) - Pubmed citation
- 8. Kupesic S, Kurjak A. Septate uterus: detection and prediction of obstetrical complications by different forms of ultrasonography. J Ultrasound Med. 1998;17 (10): 631-6. J Ultrasound Med (abstract) - Pubmed citation
- 9. Storment JM, Kaiser JR, Sites CK. Transvaginal ultrasonographic diagnosis of uterine septa. J Reprod Med. 1998;43 (9): 823-6. - Pubmed citation
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