Lithopedion

A lithopedion (also spelled lithopaedion or lithopædion; from Ancient Greek: λίθος "stone" and Ancient Greek: παιδίον "small child, infant"), or stone baby, is a rare phenomenon which occurs most commonly when a fetus dies during an abdominal pregnancy,[1] is too large to be reabsorbed by the body, and calcifies on the outside as part of a foreign body reaction, shielding the mother's body from the dead tissue of the fetus and preventing infection.

It is not unusual for a stone baby to remain undiagnosed for decades and to be found well after natural menopause; diagnosis often happens when the patient is examined for other conditions that require being subjected to an X-ray study.

The lithopedion was carried for an average of 22 years, and in several cases, the women became pregnant a second time and gave birth to children without incident.

In a speech before the French Académie Royale des Sciences in 1748, surgeon Sauveur François Morand used lithopedia both as evidence of the common nature of fetal development in viviparous and oviparous animals, and as an argument in favor of caesarean section.

[6] In 1880, German physician Friedrich Küchenmeister reviewed 47 cases of lithopedia from the medical literature and distinguished three subgroups: Lithokelyphos ("Stone Sheath"), where calcification occurs on the placental membrane and not the fetus; Lithotecnon ("Stone Child") or "true" lithopedion, where the fetus itself is calcified after entering the abdominal cavity, following the rupture of the placental and ovarian membranes; and Lithokelyphopedion ("Stone Sheath [and] Child"), where both fetus and sac are calcified.