by Chinwe Okafor

According to a new research paper in the Hong Kong Medical Journal, it has been revealed that a baby girl was born pregnant with two fetuses.

Although the incident happened in 2010, the recently published paper discusses the incredibly rare condition in detail; there have only been 200 cases ever reported.

The 8- to 10-week-old fetuses were a result of fertilized eggs from the child’s parents getting embedded in the child. Medically speaking, it’s looked at as a kind of cancer and not an actual pregnancy.

The child underwent an operation when she was only 2 weeks old, and the fetuses were successfully removed.

The condition, known as “fetus in fetu,” is very rare. It’s not even known what causes it to happen.