I've kept up my Ashtanga practice twice a week so far during my pregnancy (plus one more Hatha-y session + one of pregnancy yoga). I'm 32 weeks now and still feel comfortable doing my modified practice, but I don't know if I'm being overambitious thinking I can just carry on til baby's here.
Would love to hear others' experiences, especially if you had a regular Ashtanga or other vinyasa-based practice - does there come a point where your body just says 'enough with this now'?!