This strange occurrence happens as a result of gases building up inside the abdomen of a deceased pregnant woman. These gases, produced by bacteria during decomposition, cause the abdominal cavity to expand, putting pressure on the fetus, which then forces the fetus out through the birth canal.
Factors causing a coffin birth
Stage of pregnancy: The later the stage of pregnancy, the more likely the occurrence of postmortem fetal extrusion. This is because the fetus is larger and heavier in the later stages, making it easier to be pushed out by the gas buildup.
Time since death: The longer the time since death, the higher the probability of postmortem fetal extrusion, as bacteria have more time to produce gases, increasing pressure within the abdomen.
Position of the fetus: If the fetus is positioned head-down, it is more likely to be pushed out.
Abdominal distention: Conditions that cause abdominal distention, like obesity or fluid accumulation, increase the chances by creating more space for gas buildup.
Caitlin Doughty, a mortician and author explains that postmortem fetal extrusion can happen 48–72 hours after the death of a pregnant woman. “As the gas in her abdomen builds up due to decomposition, pressure rises to the point that it presses on the uterus so intensely that the unborn fetus is expelled or partly expelled from the mother’s body,” she says.
Accounts of postmortem fetal extrusion have been documented throughout history, with references dating back to ancient civilisations. In some cultures, a coffin birth was seen as a supernatural force or an omen of impending doom.
The true nature of postmortem fetal extrusion remained shrouded in mystery until modern scientific advancements revealed the underlying reasons for this phenomenon.
A recent discovery
In 2010, archaeologists excavating a medieval cemetery in Imola, Italy, discovered the skeleton of a pregnant woman with a hole in her skull and the remains of a fetus lying between her legs.
Upon examination, scientists concluded that this was a case of postmortem fetal extrusion. The hole in the skull, they believed, was the result of an ancient surgical procedure called trepanation, which was sometimes used to treat headaches or other ailments.
Thanks to embalming practices, coffin births rarely occur these days.