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What is lithopedion?

What is lithopedion?

Its name comes from the Greek words "litho", stone, and "pedion", child and it is a phenomenon that appears in one of every 20,000 pregnancies. Litopedion literally means stone baby.

This phenomenon occurs when an embryo attaches to any place outside the uterus and the fetus grows, for more than 12 weeks, but fails to survive and eventually dies. If the fetus is too large, it is not expelled or absorbed, but instead begins to calcify.

Calcification occurs subcutaneously and is enveloped in scar tissue. The tissues are dehydrated, calcium infiltrates and the petrification process begins. For this, it is required that aseptic conditions exist and that the optimal conditions for the precipitation of calcium occur.

If this process is asymptomatic and goes unnoticed by doctors, the fetus becomes mummified and ends up becoming a stone baby, also known as lithopedia. It may go undiagnosed for decades and may be detected by screening for other reasons.

There are different types of lithopedion:

  • Litokeliposis: the membrane of the ovule is calcified. The fetus may be in different stages of decomposition.
  • Litokelitopedion: both the fetus and the ovum membranes are calcified.
  • Common lithopedion: only the fetus is calcified.

Although it seems to be a myth, they are very rare but real cases. There are fewer than 300 documented cases in the medical literature accumulated over more than 400 years.

The diagnosis of lithopedion is rare due to the early detection of abdominal pregnancies, despite the fact that ectopic pregnancies are becoming more common.