The condition known as, “lithopedion (stone baby), is so rare that it has only been recorded approximately 300 times in medical history.
Rarely a pregnancy can form in the abdomen rather than in the uterus. When the pregnancy fails the body has no way to expel the fetus. As a result, the immune system turns the fetus to “stone,” via calcification of the tissue to protects the mother from infection.
The baby can remain in the abdomen undetected for decades.
The rate of an abdominal pregnancy is about 1 in 10,000 pregnancies and modern medical care usually identifies issues in advance.