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Can Exercise Cause Preterm Labor?

Many pregnant women worry about exercise and preterm labor. They shouldn't. Exercise does not increase the risk of preterm birth. For some women, it may even decrease the risk.

After reviewing exercise's effects on pregnancy in 2,059 healthy-weight women, research found that those who exercised were more likely to carry to term. This study allowed women to participate in randomized aerobic exercises for 35 to 90 minutes in length, 3 to 4 times per week during the duration of their pregnancy.

The study found:

  • Preterm birth was not associated with exercise.
  • Exercising while pregnant has no effect on gestational age at delivery.
  • Exercising during pregnancy is associated with higher rates of vaginal delivery.

Another study conducted with 1,502 overweight/obese pregnant women had similar findings. These women participated in randomized aerobic exercise for 30 to 60 minutes, 3 to 7 times per week during the duration of their pregnancy.

The study found:

  • Exercise was associated with lower risk of preterm birth
  • Exercise in overweight pregnant women results in higher rates of vaginal delivery

The Benefits of Exercise

"Exercise has the same long-term benefits in pregnant women as in non-pregnant women," says Marcela Smid, MD, a board certified physician in Maternal Fetal Medicine in the Department of Obstetrics and Gynecology at University of Utah Health.

Exercise helps to maintain:

  • Cardiovascular endurance
  • Muscular strength
  • Flexibility and body composition
  • Agility, coordination, and balance

Exercise also has a role in the psychological wellbeing of a pregnant person.

"Regular exercise while pregnant can cause improved mood, decreased stress, improved self image, increase in sense of control, relief of tension, and even reduced odds of postpartum depression," Smid says.

Other benefits of exercising while pregnant include:

  • 34 percent reduction in back pain when women randomize exercise throughout pregnancy
  • Possible risk reduction of pregnancy complications like gestational diabetes and preeclampsia

If it Hurts—Stop!

Exercising while pregnant is good. If you don't exercise, start! If you do, keep going! If it hurts, stop!

There is a big difference between discomfort and pain when it comes to exercising. If you feel a sharp, stabbing, or intense burning, stop your activity. Discomfort and experiencing fatigue while exercising are normal. An easy way to determine the difference between the feeling of discomfort and actual damaging pain is to stop when you have these feelings:

  • If the uncomfortable feeling goes away after you stop working a muscle, it is likely just discomfort.
  • If pain continues after ceasing activity, you may have overdone it.

Remember to make exercise fun. Personalizing your workouts is a great way to keep engaged and excited about exercising.