This is a unique and mythical occurrence comparable only to the virgin Mary giving birth to Jesus. A Led Zeppelin Pregnancy occurs when a woman is listening to Led Zeppelin at just the right frequency and volume. Since they rock so fucking hard, the sound waves penetrates the moist undergarments, travels up the birth canal, and rocks the eggs deep and hard with their solid drum beats, tails of love and loss, and thunderous riffery. The hard rocking sound waves are no match for the fragile eggs, they soon give in they are fertilized. The woman then has the honor to carry the offspring of the creators of the music of the gods.
Ed: Yo, did ya hear what happened to Sammy girl?
Joe: Na, what happened?
Ed: She had a Led Zeppelin Pregnancy, now Sammy has to raise the offspring of the gods. How about that hot shit?
Joe: Lucky bastard!
Ed: Tell me about it!