According to researchers from the Universities of Ferrara and Bologna, “The woman was somewhere between 25 and 35 years old when she died, and the fetus was at 38 weeks of development (just two weeks shy of being full term). The baby’s legs were still inside the mother’s body, but its head and upper body had dropped below the pelvic cavity. The fetus was already in its head-down orientation (the cephalic position) and was positioned for birth.”

As a side note, the woman’s skull also had a “neat and clean” hole in it. According to the same researchers, this was likely from an ancient form of brain surgery called trepanation.

Source: https://www.buzzfeed.com/crystalro/coffin-birth