A rare strip of parchment more than 10 feet (3 meters) long and adorned with Christian emblems shows chemical traces of its use by women in medieval England as a magical amulet to protect them during pregnancy and childbirth, according to a new study.

On the surface of the strip of parchment — called a “birthing girdle” or “birth scroll” — the researchers found traces of plant and animal proteins from medieval treatments used to treat common health problems during pregnancy, and of human proteins that match cervico-vaginal fluid. Those traces suggest the girdle was worn by women while they gave birth.