Which uterine abnormality is characterized by a lack of fusion limited to the superior portion of the uterine body?

The uterine abnormality characterized by a lack of fusion limited to the superior portion of the uterine body is the bicornuate uterus. This condition arises from a failure of complete fusion of the paramesonephric ducts during embryonic development, leading to a uterus that has two distinct horns and a notable indentation at the fundus.

In a bicornuate uterus, the division occurs at the superior aspect while the cervix typically remains singular, which allows for the characteristics of having two separate endometrial cavities. This anatomical structure can sometimes be associated with complications in pregnancy, such as a higher incidence of miscarriage or preterm labor, due to the abnormal shape and potential for reduced uterine volume on one or both sides.

Other uterine abnormalities do not fit the specific description provided in the question. For example, a septate uterus involves a fibrous or muscular septum dividing the uterine cavity but does not relate to a fusion anomaly in the superior aspect. The arcuate uterus, which is a more common and less clinically significant variant, features a smooth indentation at the fundal area but is a complete fusion of the uterine structures. Uterine fibroids, on the other hand, are benign tumors that can distort the shape of