Are sit-ups safe while pregnant?

During your first trimester, you can continue doing ab exercises however you gosh darn well please, be it sitting, lying down, on a ball, standing up, etc. After your first trimester, things get a little trickier and you have to get a bit more creative to work your abs. After your first trimester, you will want to avoid doing anything lying flat on your back. When you are flat on your back during your second and third trimester, your baby is put in a position to literally crush all of your internal organs which doesn't feel very good and isn't safe. If you are comfortable on a stability ball, you can continue to do crunches while lying on the ball. Just make sure to keep your chest higher than your hips throughout the exercise. Another great core exercise is the side plank which uses the muscles of your internal and external obliques (your waist). It is crucial to continue to work the muscles of your core throughout your pregnancy because it is these very muscles that are going to do the job of pushing out your baby!