It is a very strange condition that occurs in one of every 500 thousand births known as "Fetus in fetu", an exceptional case of twin-parasite. Only about 200 cases are known worldwide of atrophied fetuses that have not been formed and have been found inside the other twin, benefiting from fetal circulation, like a parasite.
The last case has been diagnosed in Hong Kong where a "pregnant" twin baby was born. Inside his belly were two fetuses, one of eight and the other of ten weeks of gestation, which had legs, arms, spine and part of the intestines formed.
Above you can see the image of a CT scan of the girl in which the spine of the fetuses is seen and that has been recorded, by its extraordinary character, in the latest issue of the Hong Kong Medical Journal.
It is extremely rare to occur, but in most cases it is diagnosed in the first years of life (89% before 18 months). Sometimes it can be detected by ultrasound in pregnancy, but it is complicated by how small the remains can be. In this case, one of the fetuses weighed 14.2 grams and the other 9.3 grams.
Barely three weeks old, the girl was operated to extract the fetuses of her brothers who were never born and was released eight days later.
They are really very impressive cases of rare cases of twins, and this is especially exceptional because it is not only the fetus of a twin brother, but two fetuses within another.
