The ‘stone baby’: For more than 50 years, she carried her unborn child inside her

It’s a rare condition that admittedly sounds like something out of a horror movie: A foetus dies, and is then calcified - essentially turned to stone - inside its mother’s body.

In June, reports of a case in Chile circulated - one that may never have been discovered if not for an unrelated injury. Now Estela Melendez, the 91-year-old resident of La Boca who went to the hospital after falling and learned shocking news, has spoken with CNN about her ordeal.

“The doctors said I had a tumour and that they needed to operate on me,” Melendez says in the video interview. But a second x-ray confirmed not a tumour, but a foetus.

This phenomenon is called a lithopedion, otherwise known as a “stone baby”. First described back in the 10th century, the calcification usually occurs when an abdominal pregnancy — one that occurs outside the womb, somewhere inside the mother’s abdomen — goes awry. Nearly all abdominal pregnancies will end in miscarriage, but if the fetus is small enough, the mother’s body can reabsorb the tissue without a problem. If the foetus is too big, surgical intervention is necessary.

And if that doesn’t happen, a lithopedion can form.

Melendez has had the small bump caused by her stone baby for over half a century now, and while it causes occasional pain, she hasn’t had any serious health issues because of it. In fact, forming a stone baby is actually a brilliant protective measure on the part of a mother’s immune system: The calcified layer that forms around the baby protects its mother from its dead tissue, which would otherwise likely cause an infection.