Sonographic characteristics of congenital uterine abnormalities and associated pregnancy.

Faulty development of the mullerian duct system results in various uterine, vaginal, and renal abnormalities. Complete or partial absence of mullerian duct fusion and/or canalization results in septate, bicornuate, or double uterus; the specific anomaly depends upon the degree of fusion and canalization. Unilateral renal agenesis is frequently associated. Three cases of uterine anomalies associated with pregnancy are presented. When a pregnancy occurs in one side of a double uterus, the nonpregnant side may simulate a solid pelvic mass, such as a leiomyoma. In anomalies where there is a communication between two uterine cavities, the nonpregnant side may require the appearance of a cystic mass. Pregnancy associated with uterine anomalies carries significant morbidity.