I proposed this on an earlier post... there seem to be a lot of players who don't want to let go of those characters they've invested so much time in, and a lot who think getting to very high levels waters down the game.
Perhaps a suitable solution for both would be a prequel. You'd play your mortal parent and the story would take you through the circumstances leading to your birth.
As Weasel suggested, you could meet some of the other NPCs parents as well. Just how DID Minsc's Boo fixation come about? What are the truths behind some of Jan's stories?
and besides, why would any god who is all knowing, and all powerful want to go through the pain of giving birth? Unless Baahl's into that kind of pain.
Thing is, Bhaal wanted to spawn as many progeny as he could. Being a woman having to give birth would not be the most efficient way to go about it! You only need one rooster in a hen house Wasn't your characters mother supposed to have been Gorion's lover, anyway?
Or from Mythral Hall, if your PC is a dwarf. I guess Bhaal could be kinky if he'd wanted to be, and change genders once or twice, but you know BioWare would never put that in their game!