Unicornuate uterus


 * Failure of one müllerian duct to elongate while the other develops normally
 * Accounts for approximately 20% of müllerian duct anomalies.
 * The embryologic predominance of the unicornuate uterus to be on the right has not been explained.
 * Spontaneous abortion rates are reported to range from 41% to 62%.
 * Reported premature birth rates range from 10% to 20%
 * Fetal survival rates, from 38% to 57% (pooled data, 40%).
 * Renal abnormalities are more commonly associated with unicornuate uterus than with other müllerian duct anomalies
 * Reported in 40% of these patients.
 * Anomaly is always ipsilateral to the rudimentary horn.
 * Renal agenesis is the most commonly reported abnormality, occurring in 67% of cases.

HSG

 * Endometrial cavity assumes a fusiform shape, tapering at the apex and draining into a solitary fallopian tube.
 * Uterus is generally shifted off of midline.

MRI

 * Unicornuate uterus appears curved and elongated, with the external uterine contour assuming a banana shape.
 * Uterine volume is reduced, and the configuration of the uterus is asymmetric.
 * Normal myometrial zonal anatomy is maintained.

Images
Patient #1

References for

 * Robert N. Troiano, and Shirley M. McCarthy. Müllerian Duct Anomalies: Imaging and Clinical Issues. Radiology 2004 233: 19-34.