Bicornuate uterus is a fusion anomaly of the mullerian ducts. During embryogenesis the paired mullerian ducts are supposed to fuse in the midline at a gestational age of 10-17 weeks to form the uterine cavity, as well as cervix, fallopian tubes, and upper 2/3 of the vagina. In bicornuate uterus there is incomplete fusion that creates 2 seperate horns just above the level of the internal os.

Mullerian duct developmental anomalies represent a wide spectrum of uterine anomalies ranging from near complete fusion to agenesis that usually are associated with infertility in clinical practice. There is a strong association of mullerian anomalies with those of the urinary system, inclusive of renal and cloacal abnormalities and exstrophy.

Imaging workup of the infertile female usually begins with hysterosalpingography or ultrasound. Sometimes a single imaging modality is not sufficient for diagnosis and patients will be evaluated with MRI. This allows the ability evaluate the entire genitourinary tract and is highly accurate in determining the anomoly type. Critical to treatment is distinguishing a septate from bicornuate uterus since the former is treated with hysteroscopic metroplasty and the latter requires an open surgical repair.