In Bulgarian folklore there exists the character of twelve Navias who suck the blood out of women giving birth , .
In the Primary Chronicle the Navias are presented as a demonic personification of the 1092 plague in Polotsk .
In Bulgarian folklore there exists the character of twelve Navias who suck the blood out of women giving birth , whereas in the Primary Chronicle the Navias are presented as a demonic personification of the 1092 plague in Polotsk .