No way! No my mares do not foal with the stallion. They are brought in and put under a camera with a breeder alert. They are turned out about day 5 to 7 for the foal, or depending on the foal and how they are all doing, etc.... I have had a couple of 'surprizes' over the years where they did foal out with the whole herd but that was a big OOPS!
I would rather have them foal in where they are watched and can be monitored and attended to immediately if need be. They stay under the camera after the foal is born too for the days they are in, just to make sure all is well.
My stallions have all been wonderful with the foals too over the years.. they babysit, allow them to bite and rear up on them, etc... when they get annoyed enough, they give the babies 'the look' and the youngsters know that it's time to move on and harrass someone else, lol