Diprosopus is a congenital defect also known as craniofacial duplication. The exact description of diprosopus refers to a fetus with a single trunk, normal limbs, and facial features that are duplicated to a certain degree. A less severe instance is when the fetus has a duplicated nose and the eyes are spaced far apart. In the most extreme instances, the entire face is duplicated, hence the name diprosopus. Fetuses with diprosopus often also lack brains (anencephaly), have neural tube defects, or heart malformations. In some cases, if the brain is formed, it may have duplicated structures.