"Before a woman delivers her child, all spiders and crawling insects of the Weirth must be driven from the room with the smoke of Sage and green Willow branches, to keep the Entropy daemonette Lolth from corrupting the child as it is born."
Before the Cataclysm the Weirth was a place of peace and beauty, great tall beings called the Alfen lived in glittering cities of crystal and silver. They were the masters of magic and wielders of god-like powers. All served Agytha and her husband Nyarlethotep, the Avatars of Law, and everything grew and flourished in harmony.
Then came Arioch, Avatar of Entropy, from the Outerdark. He had many fine words and charming songs, used to woo Agytha and tempt here to give up her virtue. He also tempted many of the Alfen and they followed his wise and wondrous ways.
When she refused him, he became angry and took revenge by teaching some of his followers new magics, powerful spells for fighting and killing, rather than building and growing, as Agytha had done.
A mighty war shook the lands of Weirth, pitting family against family, son against father, daughter against mother. The world was broken and nearly destroyed. For many years the Alfen fled the destruction, leaving the Humans, their servants and students, to fend for themselves.
Agytha and Nyarlethotep took pity on the struggling humans, who had no magic of their own, and with the help of Voorsteh, the Midwife Angel, gave birth to the Gods of Weirth to protect and succor Humankind. This angered Arioch, so he summoned a mighty daemonette named Lolth to the sacred city of R'lyeh. There, through the unholy power of widdershins, he conceived his own children to counter the powers of the children of Agytha.
That is why women pray to Voorsteh in their time of delivery, and why all spiders must be driven from the room where a child is to be born.