My insurance company are pretty vague whenever I ask them anything, and usually say to follow what you were told in training.
I wax my clients right up to their due date. I lift the head of the bed so they're not lying flat, work super quick (I try not to have them lying down for more than about 15 mins), have a glass of water on hand for them, tell them to let me know at any point if they feel uncomfortable and get them to sit up for a few minutes after I'm done before they jump off the bed to make sure they don't get dizzy.