Pregnancy should be an exciting time during which you develop healthy exercise and nutrition habits. If you are pregnant and want to start or continue exercise, you should be able to if your pregnancy is normal and low risk. Take it slow and stop exercising if you experience pain, fatigue or overheating. Discuss any pain or unusual symptoms with your doctor.
Misconceptions
In his thorough and helpful book, "Exercising Through Your Pregnancy," Dr. James Clapp outlines a number of common misconceptions regarding prenatal exercise. Previously, it was wrongly thought that prenatal exercise may cause miscarriage, fetal overheating in the womb, placental abruption, stillbirth, and low birth weight. Some of these myths were passed on simply due to ignorance or unfounded fears, like old wives' tales. Others were based on faulty medical research that was primarily performed on animals. Since the mid-1990s, medical studies on human subjects have shown that animal pregnancies do not always correlate with human pregnancies. By studying large groups of human subjects throughout pregnancy, doctors and researchers have begun to disprove these common pregnancy myths.
Benefits for Mothers
Prenatal exercise benefits women in five particular areas: the heart and circulatory system, lung and placental gas support, body temperature and sweating, metabolic and hormonal responses, and muscle, ligament and bone adaptations. Blood volume, plasma volume and red cell volumes of exercising pregnant women are 10 to 15 percent higher than women who do not exercise. Body tissues are more able to take up and use oxygen. Pregnant, exercising women have increased abilities to deal with heat stress, since they are more able to eliminate excess heat. Pregnancy and exercise combined provide higher amounts of glucose and oxygen for the baby. Finally, prenatal exercise may reduce laxity of ligaments and improve overall muscle strength and tone.
Benefits for Baby
Recent studies show that exercise has a positive influence on fetal growth and development. About ten minutes into exercise, the fetal heart rate will increase, and will continue to increase as mom exercises. This is a normal response that is not dangerous to the baby. In fact, newborn babies whose mothers exercised during pregnancy show an increased ability to adapt to life outside the womb. Frequent, intense exercise may cause a reduced body fat content, which may cause lower birth weights. Most babies' body fat levels are about 14 percent, whereas those with exercising moms usually have a 9 percent body fat level. Again, this is not harmful to the baby and may even decrease chances of obesity later in life. Exercise also has positive effects on the development of the fetal nervous system, which leads to a smoother transition from womb to outside world.
Contraindications
The American College of Obstetricians and Gynecologists recommends that women who have preexisting cardiac, vascular, pulmonary or thyroid diseases discontinue exercise during pregnancy. Women who have had three or more miscarriages should discontinue exercise until the second trimester. Women who experience regular bleeding during the second and third trimesters, whose water has broken, or whose babies are in a breech position in the third trimester should also discontinue exercise. Some other health conditions, such as as diabetes, obesity, hypertension, anemia or back, joint and muscle problems, may also exclude exercise from a woman's pregnancy. Placental disorders, such as placenta previa or placental abruption, are other reasons to discontinue exercise.
References
- "Exercising Through Your Pregnancy"; Dr. James Clapp, M.D.; 2002
- "Expecting Fitness"; Birgitta Gallo; 2000
- The American Congress of Obstetricians and Gynecologists: Exercise During Pregnancy
