as long as you do your kegals excersises you will be fine. Do them right after birth if you can. Get your PC muscle strengthened BEFORE birth. I think that will make the most impact, cause if your muscles are strong to start with they have a better chance of bouncing back quicker. But the PC muscles are a sure way to keep your vag strong and tight.
My mom has had 4 deliveries and she swears by it.
Look up an excersise routine for PC muscles on the net.