In every pregnancy, a woman starts out with a 3-5% chance of having a baby with a birth defect. This is called her background risk. This sheet talks about whether exercise may increase the risk for birth defects above that background risk. This information should not take the place of medical care and advice from your health care provider.

Is exercise safe for all pregnant women?

The American College of Obstetricians and Gynecologists (ACOG) recommends that women without medical or pregnancy complications consider at least 30 minutes of moderate exercise on most days, if not all, days of the week.

You may not be able to exercise while pregnant if you: have experienced preterm labor, have ongoing vaginal bleeding, feel contractions, or have other pregnancy related complications.

If you have a history of any medical problems such as heart or lung problems or high blood pressure, you should also check with your health care provider before starting or continuing an exercise program.

Does exercise harm the developing baby in any way?

Currently, there is no evidence to suggest that exercise can harm your pregnancy. It has not been shown to increase the chance of miscarriage, birth defects, or premature labor. Studies show no relationship between exercise and fetal distress or fetal heart rate changes. One study found that moderate to high intensity exercise in the later stages of pregnancy can lead to smaller, leaner babies that are still within the “normal range”.

Will exercise be more difficult during pregnancy?

Your body will go through many changes throughout pregnancy that could affect your ability and tolerance to exercise. Your body works harder to give enough oxygen to the baby as it develops, so you have less oxygen available for exercise. As the baby grows and your womb gets larger, your sense of balance shifts so that you may need to adjust your posture. Joints around your pelvis loosen to make room for the birth of the baby; so there’s a better chance of strains or sprains. Also, your blood volume and heart rate increase to allow nutrients and oxygen to be given to the baby. This change in blood flow could make you feel lightheaded.

What are the benefits of exercising during pregnancy?

Exercise is important for your health. It has been shown to allow faster weight loss after pregnancy, and improve mood and sleep patterns. Exercise may help prevent or treat gestational diabetes. Exercise might also ease some of the common discomforts of pregnancy such as constipation, backache, fatigue, leg swelling, and varicose veins.

What are some guidelines for exercising safely during pregnancy?

The following guidelines apply if your pregnancy is low risk and you have checked with your health care provider to make sure you can continue an exercise program.

  • Regular exercise, at least 3 times a week, but preferably every day.
  • During the second and third trimesters, avoid exercise that involves lying flat on your back because this allows less blood flow to your womb.
  • Avoid exercising to the point of exhaustion or breathlessness. This is a sign that your baby and your body are getting less oxygen.
  • Be aware that your sense of balance will change throughout pregnancy, which could lead to falls.
  • Do not do exercises that can cause trauma to the abdomen.
  • Drink plenty of fluids before and during exercise.
  • Avoid overheating your body, especially in the first trimester.

What types of exercise are best during pregnancy?

Most women can continue their pre-pregnancy exercise routine during pregnancy, but you may need to modify some activities. Listen to your body and stop when you feel too tired or if you feel dizziness, headaches, muscle weakness, nausea, chest pain, fewer fetal movements or have contractions. Don’t get discouraged: even mild to moderate exercise can help your fitness level and your mood.

In general, you can safely participate in a wide range of recreational activities. Non-weight bearing exercises such as stationary cycling, swimming, or water aerobics are easiest on your body throughout your entire pregnancy.

Contact sports such as ice hockey, soccer, and basketball could result in trauma to both you and your baby. Also, your risk of falling during activities such as gymnastics, horseback riding, and downhill skiing may be higher during pregnancy as a result of balance changes. Because of decreased oxygen, scuba diving and exercising at altitudes above 6,000 feet may not be recommended.

If I am training at an elite level, will pregnancy hinder my performance?

As an athlete, you may need to modify your training program for safety in each stage of pregnancy. While there may be risk involved in physical activity for some pregnant women, most health care providers believe that the benefits of being active far outweigh the risks, even for those who wish to continue participation at an elite level. Your pre-pregnancy levels of fitness, as well your particular sport, must be taken into account when planning the intensity, duration, and frequency of exercise during pregnancy.

If you regularly consult with medical advisors, and follow medical advice regarding your training, it is unlikely that your exercise program or sport will cause problems. However, it is typically advised that you not exercise at greater than 75% of your maximum heart rate during pregnancy. Discuss the safety and concerns of your particular sport or training program with your health care provider.

Studies have found that some athletes use supplementation to enhance performance. Few studies have been done to demonstrate the safety of various supplements during pregnancy. Be sure to consult a sports nutritionist as well as your physician if you are taking any sort of supplementation

When can I begin to exercise after giving birth?

Talk to your health care provider to find out how soon you can begin to exercise after giving birth. Your body will continue to go through changes from your pregnancy for many weeks after your baby is born. How long you should wait will depend on a few factors, including how active you were able to be during pregnancy, any health problems you have and what type of delivery you had.

Does exercise affect breastfeeding?

Exercise has not been found to affect breastfeeding. In general, you will still produce the same amount of milk whether you exercise or not. However, it is extremely important to drink a lot of water when breastfeeding, especially if you are exercising. Be sure to discuss all you choices for breastfeeding with your health care provider.

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