A bicornuate uterus describes a uterus that is shaped irregularly. A bicornuate uterus is described as heart-shaped, appearing to have two sides instead of being one hollow cavity. It’s rare, congenital condition that can cause complications during pregnancy. It can only be treated with surgery.

a uterus that is more or less completely divided into two lateral horns as a result of imperfect union of the paramesonephric ducts; it differs from septate uterus, in which there is no external mark of separation; in bicornate uterus, the cervix may be single (uterus bicornis unicollis) or double (uterus bicornis bicollis).

A bicornuate uterus is divided according to the involvement of the cervical canal: bicornuate bicollis : two cervical canals; central myometrium extends to the external cervical os bicornuate unicollis: one cervical canal; central myometrium extends to the internal cervical os

Bicornuate uterus is typically classified based on whether or not the division extends to the external cervical os. Bicornuate uteri with a division above the os are called bicornuate unicollis and those with a divided os are called bicornuate bicollis.