This website says (and I’ve heard it countless times):
In his sefer Shulchan Melachim (page 35b), R. Moshe Tzvi Landau writes that it is customary to place the Sefer Noam Elimelech, beneath the head of a mother during labor. This segulah has been practiced for hundreds of years and there are countless stories of miracles involving the Rebbe R. Elimelech and the Sefer Noam Elimelech.
My question is: does anyone know why? Why is this Sefer specially connected to child birth? I am curious how this came to be.