Exercise and Pregnancy by Renée Mason, MD

Exercise and Pregnancy?

The answer is Yes, Yes, Yes! There are very few absolute contraindications to being active during your pregnancy…. we will talk about this a little later. If you already have an exercise regimen, keep it up, unless of course you are scuba diving, jumping from airplanes, playing contact sports or sweating it out in hot Pilates/yoga.  If you haven’t been very physically active, you can still start during pregnancy. Often times women develop healthier habits during pregnancy and are motivated to begin exercising. Use this motivation to  make some lifestyle changes that will benefit you now and during the postpartum period.

The American College of Obstetrics and Gynecology recommends at least 20-30 minutes of moderate activity most days of the week.  Moderate activity is best quantified as the ability to talk  when exercising.

Regular exercise during an uncomplicated pregnancy maintains or improves physical fitness and cardiorespiratory function. Psychological well-being may also be enhanced.

Multiple studies support the benefits of exercise during pregnancy. Muscle strength, balance, endurance, flexibility and body composition are improved or maintained. Low back pain and pelvic girdle pain can be prevented or reduced. The risk of developing gestational diabetes and delivering a macrocosmic ( large for gestational age) infant are reduced which also reduced the risk of cesarean delivery.  Recent studies also suggest that the risk of pre-eclampsia ( high blood pressure in pregnancy) is reduced with increasing levels of physical activity before and during early pregnancy. Another big bonus is the reduction is the duration of the first stage of labor.

Many patients  are worried about the risks of exercising during pregnancy. There are a lot of myths out there…how many of you have heard you shouldn’t raise your arms above your head while pregnant because it will cause the cord to wrap around the babies neck? Total myth…but I’ve been asked about it several times. So go ahead and raise your arms…it will not cause a nuchal cord.  Many patients also ask if activity will increase the risk of miscarriage. Unfortunately, miscarriage rates are much higher than people realize. The rate may be as high as 20-25%, but it is not related to activity or exercise. For women at high risk of miscarriage or preterm birth, exercise, especially heavy lifting or strength training should be restricted. For low risk pregnancies, the rate of miscarriage or preterm delivery is not increased.

Another concern that is frequently expressed is the risk of raising core body temperature. Maternal core temperature of 102.2F in the first 4-6 weeks of pregnancy has been associated with increased risk of neural tube defects. It is very unlikely that you can raise your core temperature this high with normal levels of exercise. Hot yoga/pilates  or running a marathon in a hot environment should be avoided as unsafe levels of hyperthermia are a possibility.

Also heard…will exercise decrease blood flow to the placenta? Blood flow may preferentially be directed to the working muscles during exercise but evidence suggests that the normal fetus compensates for any transient changes in placental blood flow and is not at risk of harm.

  1. So who should not exercise while pregnant?
  2. Absolute contraindications include:
  3. Significant heart disease
  4. Restrictive lung disease
  5. Incompetent cervix or cerclage
  6. Multiple gestation at risk for premature labor
  7. Persistent second or third trimester bleeding
  8. Placenta prevue after 26 weeks gestation
  9. Premature labor in current pregnancy
  10. Ruptured membranes
  11. Pre-eclampsia or pregnancy- induced hypertension
  12. Severe anemia

You will experience many physiologic changes during pregnancy that may make it necessary for you to modify your activity.  Nausea, reflux, orthostatic hypotension ( drop in blood pressure), hyper mobile joints and changes in gravity may make some postions/poses challenging or even unsafe. Make sure to stay well hydrated and avoid becoming overheated, and of course if any exercise feels uncomfortable or painful stop and re-evaluate. If at any time you  experience vaginal bleeding or leaking of fluid, shortness of breath or faintness, chest pain, muscle pain or contractions, please be evaluated by your provider.

All in all, exercise in pregnancy offers so many benefits and minimal risks. Women with uncomplicated pregnancies should be encouraged to engage in physical activity during and after pregnancy. Check with your provider before beginning an activity, then find something that is motivating, supportive and most of all fun for you.