I bought 5 different prenatal exercise DVD's & was REALLY disappointed in all of them. They were way too slow/easy. The best of the bunch was Denise Austin's DVD, but even that was not great. They are ok if you're not an active person to begin with, but I found I got a MUCH better workout doing a brisk walk, swimming, & prenatal water aerobics. My Dr. told me I could continue doing cardio untill my heartrate got up to 150, so I wore a heartrate monitor in more "intense" classes like spin & backed off when I got near 150. Hope this helps!
Re: exercise
https://www.amazon.com/Prenatal-Yoga-Shiva-Rea/dp/B0000BYNMH/ref=sr_1_1?ie=UTF8&s=dvd&qid=1254625970&sr=8-1-spell
I used this one and really enjoyed it.