There are a few exercises you should avoid once you're pregnant. One of the obvious ones-no contact sports. I don't care if it's Thanksgiving, once you're pregnant, do not get out on the field and play football with your family. Avoid downhill skiing, soccer, rugby, whatever your sport of choice is, save it until after baby is due. Also as your belly grows it's going to be uncomfortable to be lying on your belly so avoid the kind of up dog poses where your belly may be on the floor once it becomes uncomfortable. At some point it's also going to be uncomfortable to be lying flat on your back. It's simple. Just either lie on your side for whatever you need to do or use an incline. If you're doing a bench press, instead of lying on a flat bench, get an incline bench instead. And when you're lifting weights, maybe stop using a barbell. Use dumbbells instead, use machines at the gym or get a spotter. The last thing you want is to have a big heavy bar over you that you can't control if it drops down on you. You and baby are not going to enjoy that impact. If you use dumbbells, you can very easily push them out of the way if you start to lose control. So once you're pregnant, no contact sports, don't lie on your belly, don't lie on your back once it's uncomfortable and think about switching to machines or dumbbells if your weight training or find yourself a spotter.