I would assume that if you are uncomfortable with the idea of smoking marijuana while you're pregnant, you're off to a bad start. (The whole bad vibe thing is never good.) Our brains are hard wired for our specific needs, perhaps for some pregnant mothers smoking pot would be harmful and for others, beneficial. We didn't have a vape at the time, or she would have used that as opposed to smoking. You know your body, or at least you should, so you'd have to be a judge of that...and yeah, there won't be any studies on that, I don't think, so it's always going to be a matter of debate. Peace.