Kegels during/after pregnancy

Hey. Well let me start off by saying that I am not pregnant, just wondering something.

I know female Kegel excersizes can strengthen the vaginal walls and keep it "tight". Well I was wondering what the effect of Kegels are on a pregnant woman. I would think that Kegels performed close to the delivery date would make labor harder, seeing as it would tighten the vaginal walls. Is this right?

Also, I was wondering when it is safe to do Kegels after birth. I know how much labor stretches the vagina, and I'm under the impression that Kegels can help it get back to, or at least close to, how it was before. Im thinking that a woman should wait a little while, seeing as there are probably many small tears that need to heal after child birth. Or would Kegels help the healing?

I dont know why Im so curious about this, i would just like to know. Thanks!

monie