There are prostoglandins (sp?) in EPO - same as what is in semen - that helps induce labour. Obviously sex would be the best way to get them (and hubby likes that idea!) but not always practical or comfortable when you feel like a beached whale! Sometimes it's much nicer to insert, roll over and go to sleep! :LOL: Laying down helps the stuff stay in after the shell dissolves - you want to keep it in as long as you can.