The only reasons that swimming would not be an acceptable exercise are:
- If your practitioner told you not to exercise.
- If your water had broken.
It should be noted that diving from the high dive is generally not advised.
Swimming is enjoyed by many pregnant women, most notably for the feeling of weightlessness in the water. This is particularly true in the third trimester. This can also make aerobic exercise safer than on dry land because the water provides more cushion for your joints.
After you've done your work out, consider spending an extra few minutes working on your relaxation. Try floating on your back and just clearing your mind. Imagine your baby floating in his or her own swimming pool.
The hardest part can be finding a bathing suit. While maternity swim suits are easier to find, many women still worry about being in one while pregnant.
Exercise and Fitness. American Congress of Obstetricians and Gynecologists. November 2006.