I know it isn't yoga but stay away from the pilates tv 'pregnancy' DVD. I found it to be unsafe. I had not ever heard of them and thought it looked ok on the box. There was a so-called expert, (who did not lead the exercises and who was pregnant herself) but she would only offer the advice to adapt the exercise half way through the move - after you have already twisted in a way you shouldn't etc. So I found it unsafe.

Good luck and I hope you find one you like