Often times, when a lady finds out she is pregnant, her first thoughts are to do crunches and planks and Pilates and any abdominal exercises she can dream up. Her reasoning being that she wants to keep her shape as much as possible. While this is understandable, be at peace that Mother Nature knows what she is doing with your shape. Don’t worry so much about how you look, but how you feel. Once you’ve had your little darling, you can again focus on your shape! In the mean time, avoid intense abdominal workouts because:
Your growing belly is already putting strain on your ab muscles—your abs are already getting a workout by keeping your spine neutral (so you don’t have back pain) and by supporting your womb all day long. Also, tight abdominals don’t leave much room to breathe (literally) in the third trimester. If these worries don’t convince you, be aware that tight abdominal muscles can actually split apart during pregnancy. The rectus abdominus, the long (six pack) muscle that stretches from your sternum to your pelvic bone is connected in the middle by fascia (known as the linea alba). As your baby grows and needs more space, it is not unheard of for the linea alba to split. This is not impossible to heal after pregnancy, but it is uncomfortable and takes a lot of work.
SO, instead of crunching those stomach muscles during a workout, think of LENGHTENING the abdominals. Stretches that arch the back, like up dog, will release the strain under the rib cage, where the fascia attaches to the rectus abdominus, and will give a little more space to your growing fetus (and your own internal organs!)