Hey Viparita, Shiva Rae does a great prenatal DVD (although her style is not for everyone

). I usually recommend people check out Sara Holliday as a good allrounder. She breaks down her DVDs into prenatal for first, second and thrid trimesters - called Sarah Holliday's Prenatal Yoga.
She has a great relaxed style but the yoga is mainly for people that haven't done much yoga before they got pregnant, so if you regularly practise and want something stronger then this might not be for you. I'm pretty sure that you can check her out on Amazon.com