Why To Exercise (During Pregnancy) Today: Ob-Gyns Say It’s Best Time To Boost Health

For pregnant women, Dr. Nathan Fox recommends an average of 20 to 30 minutes of moderate-intensity exercise four or five times a week. (il-young ko/Flickr)
For pregnant women, Dr. Nathan Fox recommends an average of 20 to 30 minutes of moderate-intensity exercise four or five times a week. (il-young ko/Flickr)

Yes, they've told us this before: If you're pregnant, you needn't refrain from exercise. But now, the influential (and fairly conservative) professional group of U.S. obstetricians and gynecologists is saying it even more forcefully: If you're pregnant and facing no complications, you really should exercise — it's the ideal time to improve your health, including your weight.

In an updated committee opinion, the group, the American College of Obstetricians and Gynecologists (ACOG)says: "Women with uncomplicated pregnancies should be encouraged to engage in physical activities before, during, and after pregnancy."

The list of recommended activities includes: walking, swimming, stationary cycling, low-impact aerobics, yoga (modified and not hot), pilates (also modified), running, jogging, racket sports and strength training, and all with the usual caveats to check with your doctor first.

Importantly, the opinion says: "Some patients, obstetrician–gynecologists, and other obstetric care providers are concerned that regular physical activity during pregnancy may cause miscarriage, poor fetal growth, musculoskeletal injury, or premature delivery. For uncomplicated pregnancies, these concerns have not been substantiated..."

Here are the full set of ACOG's updated recommendations:

• Physical activity in pregnancy has minimal risks and has been shown to benefit most women, although some modification to exercise routines may be necessary because of normal anatomic and physiologic changes and fetal requirements.
• A thorough clinical evaluation should be conducted before recommending an exercise program to ensure that a patient does not have a medical reason to avoid exercise.
• Women with uncomplicated pregnancies should be encouraged to engage in aerobic and strength-conditioning exercises before, during, and after pregnancy.
• Obstetrician–gynecologists and other obstetric care providers should carefully evaluate women with medical or obstetric complications before making recommendations on physical activity participation during pregnancy. Although frequently prescribed, bed rest is only rarely indicated and, in most cases, allowing ambulation should be considered.
• Regular physical activity during pregnancy improves or maintains physical fitness, helps with weight management, reduces the risk of gestational diabetes in obese women, and enhances psychologic well-being.
• Additional research is needed to study the effects of exercise on pregnancy-specific outcomes, and to clarify the most effective behavioral counseling methods and the optimal intensity and frequency of exercise. Similar work is needed to create an improved evidence base concerning the effects of occupational physical activity on maternal–fetal health.

Raul Artal, M.D., the main author of the new committee opinion, said that unlike in previous eras, pregnancy today "should not be looked at as a state of confinement." He said in an interview that only a mere "16 percent of pregnant women engage in physical activity" and noted that the obesity rate among women of reproductive age is alarming. (Based on 2011–2012 data, the prevalence of obesity in women ages 20-39 in the U.S. is 31.8 percent and it's 58.5 percent when the overweight and obese categories are combined, according to the ACOG report.)

Obviously, problems with obesity in pregnancy aren't new, and ACOG has already issued recommendations on the issue, so why the update now?

"I strongly believe that pregnancy is an ideal time to initiate an exercise program," said Artal, professor and chair emeritus of the department of obstetrics, gynecology and women's health at St. Louis University. "Women have easy access to medical care in pregnancy more than any other time during their lives. They have more medical supervision than any other time in their lives. When else does a women have eight, 10 medical visits a year?"


He said this update is essentially more emphatic than earlier recommendations.

"Now we are more definitive in our advice," Artal said, noting that the benefits of exercise for pregnant women include maintaining physical fitness, improving longevity, helping with weight management and preventing diabetes in women who are overweight or obese. Also, he said: "It helps them with preventing hypertension and other sedentary lifestyle co-morbidities."

ACOG also put out a new practice bulletin on obesity in pregnancy, which it calls "the most common health care problem in women of reproductive age."

Obesity, ACOG notes, can lead to a range of problems, including: increased risk of miscarriage, premature birth, stillbirth and having a baby with a birth defect. Obese pregnant women are at an increased risk of cardiac problems, sleep apnea, gestational diabetes, preeclampsia and venous thromboembolism, or blood clotting in the veins. The cesarean delivery rate is also higher for obese women, and cesareans pose greater dangers for obese women than for normal-weight women because of increased risks associated with anesthesia, excessive blood loss, blood clots and infection at the incision site. Moreover, the negative impacts on the fetus are long-term: obesity in pregnancy may cause the newborn to have a medically complicated life, because the fetus is directly impacted by maternal obesity.

American College of Obstetricians and Gynecologists Practice Bulletin, 2015
American College of Obstetricians and Gynecologists: Practice Bulletin, 2015

However, the ACOG bulletin says: "Obese women who have even small weight reductions before pregnancy may have improved pregnancy outcomes."

Based on guidelines issues by the Institute of Medicine, ACOG recommends the ideal weight gain for overweight pregnant women ranges from 15-25 pounds, and the range for obese pregnant women is from 11-20 pounds.

Of note, the group al so says that motivational interviewing (which we've reported on here) has been successful "to promote weight loss, dietary modification, and exercise."

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Rachel Zimmerman Reporter
Rachel Zimmerman previously reported on health and the intersection of health and business for WBUR. She is working on a memoir about rebuilding her family after her husband’s suicide. 



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