*A 9-lb baby girl born in Hong Kong is the 1 out of 500,000 born with a condition called fetus-in-fetu. According to ABC News, it occurs after a partially developed fetus becomes incorporated into a normally developing fetus (its twin) in the womb.
The rare condition was detailed in a case study published in the Hong Kong Medical Journal this month.
The mass was between the girl’s liver and left kidney, and it included two partially formed fetus-like structures, one weighing half an ounce and the other weighing a third of an ounce.
Looking at the fetuses in the diagram pictured below, doctors determine they could’ve been up to ten weeks old before they stopped growing. The study showed each structure included a spine, intestines, bones with bone marrow, “primitive” brain matter, a rib cage and an umbilical cord
As theories go, there is one for this. The study authors say the partially formed fetuses and the baby girl shared the same DNA, fitting a popular theory that the woman was initially pregnant with identical triplets.
Read more about this fascinating story here.