Destination maternity and pea and the pod have classes. You'd have to sign up through Baylor Tom Landry Fitness center which also offers prenatal yoga.
I tried to find a place in the Plano/Frisco area, and could never find anything that fit my schedule (and I'm a teacher, so it isn't like I have a difficult schedule, I just can't go at 10am on a Tuesday). I finally just ordered some DVDs. They are actually pretty good. I did hot yoga every day until I found out I was pregnant, so I didn't think I would like doing DVDs, but it really isn't that bad!
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Re: Prenatal Yoga
Sorry, I dont have any personal recommendations, but i've been looking into trying to find a class as well in the same area!
The only ones I've really found are the "Mamaste Yoga" or classes at "The Move Studio"
https://www.mamasteyoga.com/
https://www.movestudio.com/
I know i'm not much help, but hopefully someone can give us some good recommendations!