Pregnancy comes with wonderful surprises -- the first time you feel your baby move, for example. Some surprises, however, aren't so wonderful. You probably expected your back to ache and your ankles to swell, but rib pain and muscles spasms may be unexpected -- and unwelcome -- surprises.

During your first trimester of pregnancy, your body mostly undergoes invisible, chemical changes. By the second and third trimester, your growing belly causes aches and pains, but your first 12 weeks can pose challenges because of hormonal shifts, nutritional needs and low blood pressure.

Mothers-to-be expect a growing belly as their pregnancy progresses, but their new chubby cheeks might be an unwelcome surprise. As women enter their third trimester, edema, or swelling, is common, and it can affect every area from the cheeks down to the ankles.

As important as it is to pamper yourself during pregnancy by eating well, getting regular exercise and even taking an occasional trip to the spa, steam heat can be dangerous for your baby. This is a rather “hot” topic in some circles, given the popularity of hot tubs, saunas and steam rooms.

Staying fit while pregnant not only reduces the risk of putting on too much weight, but it also prepares your body for labor and the birth of your baby. Staying fit while pregnant also helps you bounce back to your pre-baby weight and size a lot quicker.

During pregnancy, not only can exercise improve your mood but it may also make delivery easier. The amount of calories you burn during exercise when you are pregnant varies because you most likely are not working out at the same exertion level as you did prior to pregnancy.

It is not bad to walk too much during pregnancy. In fact, walking is one of the best ways to get exercise during pregnancy. Staying active is beneficial for you and baby. Getting started on a regular exercise program during pregnancy depends on your level of fitness before you became pregnant.

Exercise is generally safe during your entire pregnancy. However, do not start exercising until your doctor gives you permission after your first prenatal appointment.

Pilates is a form of exercise that helps to restore correct postural alignment, release tension and develop suppleness and strength.

Pregnancy is an added stress to your body, and regular exercise can prepare you to better handle the new load. If you did resistance training before you became pregnant, resistance training to tone your arms during your pregnancy is safe to do as long as you and your baby are otherwise healthy.

If you're a runner, pregnancy doesn't have to stop you from enjoying your favorite form of exercise. In fact, the American Pregnancy Association says women who jog during pregnancy may gain less weight and have shorter labors than nonrunners. Still, you need to take certain precautions to jog safely while pregnant.

Whether you're a pregnant woman trying desperately to hold onto that pre-baby figure or are fully embracing your new ever-changing body, exercising regularly should be at the top of your to-do list throughout your pregnancy. Exercise during pregnancy will not only help keep weight gain at bay but may also benefit baby.