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1. Exercise in pregnancy
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2. Table of contents
 Physiologic changes in pregnancy
 Type, intensity, and frequency of exercise
 Benefit of exercise in pregnancy
 Contraindications of exercise in pregnancy
 Warning signs to terminate exercise while pregnant
 Maternal advice after exercise recommendation
 Exercise in postpartum

3. Physiologic changes in pregnancy
 Nutritional requirement
 Cardiovascular changes
 Respiratory changes
 Mechanical changes
 Thermoregulatory changes
 Metabolic changes

4. Nutritional requirement
 After the 13th weeks of pregnancy, about 300kcal per day
are required to meet the metabolic needs of pregnancy
 This energy requirement is increased through exercise.
 In weight bearing exercise, such as walking, the energy
requirement progressively increases with the increase in
weight during the course of the pregnancy.
 A related consideration to nutrition and exercise during
pregnancy is adequate carbohydrate intake.
Artal et al, 2003

5. Cardiovascular changes
 Pregnancy induces
– increase in maternal blood volume, cardiac output, and
resting pulse
– decrease in maternal systemic vascular resistance.
– Hemodynamics depends on position
– Cardiac output in third-trimester pregnancy is maximal
– in the left or right lateral recumbent position.
– Decreased cardiac output
– Supine position
– Motionless standing
Clark et al, 1991
Jovanovic-Peterson et al, 1989

6. Respiratory changes
 During pregnancy minute ventilation increases by almost
50%, largely as a result of increased tidal volume.
– increase in arterial oxygen tension to 106-108 mmHg in the first trimester,
decreasing to a mean of 101-106 mmHg by the third trimester.
– increase in oxygen uptake, and a 10-20% increase in baseline O2 consumption.
– Because of the increased resting oxygen requirements and the increased work of
breathing brought about by physical effects of the enlarged uterus on the
diaphragm, there is decreased oxygen available for the performance of aerobic
exercise during pregnancy.
– in some fit women, there do not appear to be associated changes in maximum
aerobic power or acid-base balance during exercise in pregnancy when
compared with the nonpregnant state
Artal et al. 1986, Prowse et al.1965
Templeton et al,1976

7. Mechanical changes
 The enlargement of uterus and breasts that occurs
during normal pregnancy results in a shift in the
physical center of gravity in the pregnant woman.
– loss of balance may prove dangerous
 Hormonal influences may result in generalized
increases in joint laxity, predisposing the pregnant
woman to mechanical trauma or sprains.
Calguneri et al. 1982, Artal etal.1991

8. Thermoregulatory changes
 Both basal metabolic rate and heat production
increase during pregnancy
 Teratogenecity
– 39.2°C, with hot tub use in early pregnancy
– an increase in maternal core body temperature during
embryogenesis exceeding 1.5°C has been observed to cause
cessation of neuronal mitotic cell growth in the ependymal
layer of the developing brain.
– Nonpregnant women exercising at 70% of maximal effort on
a treadmill for 20 minutes, the core body temperature rose
by an average of 1.5°C.
– Fit individuals are known to thermoregulate their core
temperature more efficiently.
Hytten et al.1980, Artal et al.1991, Edwards et al.1986, Milunsky et al.1992

9. 2002 ACOG recommendation
Exercise in pregnancy
 In the absence of either medical or obstetric
complications during pregnancy
 women should perform 30 minutes or more of
moderate-intensity exercise on most, if not all,
days of the weeks.
 Moderate exercise
– Defined as activity for 30 or more minutes a day, 5 or more
days a week
– ex. : Brisk walking, bicycling, vacuuming, gardening, or any activity
that causes small increases in breathing or heart rate
ACOG, 2002
Centers for Disease Control, US physical activity statistics: definitions. 2006

10. Type of exercise
Safe Avoid
Aerobic exercise
Progressive resistive strengthening
Stretching exercises
Yoga
Stationary bicycling
Jogging
Walking
Stair climbing
Treadmill use
Water exercise
Swimming
Supine position after the first
trimester
Motionless standing
Recreational sports with a high
potential for contact, such as ice
hockey and baseball
Increased risk of falling, such as
horseback riding and gymnastics
Advised not to scuba dive because
the fetus is at risk of decompression
sickness
Artal et al. 1991, Clark et al.1991, Camporesi et al. 1996 , ACOG 2002

11. Intensity of exercise
 ACSM(American college of sports medicine) recommend that
intensity should be 60-90% of maximal heart rate or 50-85% of
either maximal oxygen uptake or heart rate reserve.
 60 % of maximal heart rate or 50% of maximal oxygen uptake
– for most pregnant women who did not engage in regular exercise
before pregnancy
 70% of maximal heart rate or 60% of maximal oxygen uptake
– for those who wish to continue to maintain fitness during pregnancy.
Artal et al, 2003

12. Intensity of exercise
Daries et al, 2003

13. Frequency of exercise and rate of progression
 Previously sedentary women
– Start with 15 min of exercise three times a week
– Gradually increase to 30 min four times a weeks at low to
moderate intensity
 Active women
– Keep their routine exercise or perform at least moderate- to-
vigorous exercise
– Four times a week in sessions of 30min or more
 Atheletes or women who have higher fitness status
– Evaluated individually
– The intensity of exercise like running should be reduced
Davies et al, 2003

14. Benefits of exercise and activity during pregnancy
 Decreased chance of preeclampsia, second leading
cause of maternal death
 Decreased chance of operative delivery
 Decreased chance of developing gestational diabetes
 Improved mood
 Reduction of pregnancy discomforts- backache and
lower extremity edema
 Possible prevention of type II diabetes
 Possible prevention of chronic hypertension
ACOG, 2002

15. Pre-eclamapsia
Tanya et al., 2003

16. Pre-eclamapsia
Kasawara et al., 2012

17. Tinoloy et al., 2014

18. Deomendoz et al., 20140

19. Exercise intervention (cesarean delivery)
Deomendoz et al., 2014

20. Birthweight
Juhl, et al, 2010

21. Gestational diabetes mellitus
 Epidemiologic data suggest that exercise may be
beneficial in the primary prevention of gestational
diabetes, particularly in morbidly obese women (BMI >33)
 The American Diabetes Association has endorsed exercise
as “a helpful adjunctive therapy” for gestational diabetes
mellitus when euglycemia is not achieved by diet alone
 Vigorous activity : RR, 0.77 (95% CI, 0.69-0.94).
 Brisk walking pace : RR, 0.66 (95% CI, 0.46-0.95)
compared with an easy pace.
Dye et al, 1997
Jovanovic-Peterson et al 1996, Bung et al.,1996
Zhang et al, 2006

22. ACOG contraindications to exercise in pregnancy
 Hemodynamically significant heart disease
 Restrictive lung disease
 Incomplete cervix/cerclarge
 Multiple gestation at risk for premature labor
 Persistent second- or third trimester bleeding
 Placenta previa after 26weeks of gestation
 Premature labor during current pregnancy
 Ruptured membranes
 Preeclampsia
ACOG,2002

23. ACOG relative contraindications to aerobic
exercise during pregnancy
 Severe anemia
 Unevaluated maternal cardiac arrhythmia
 Chronic bronchitis
 Poorly controlled type 1 diabetes
 Extreme morbid obesity
 Extreme underweight (BMI < 12)
 History of extremely sedentary lifestyle
 IUGR in current pregnancy
 Poorly controlled hypertension
 Orthopedic limitations
 Poorly controlled seizure disorder
 Poorly controlled hyperthyroidism
 Heavy smoker
ACOG,2002

24. Warning signs to terminate exercise while pregnancy
 Vaginal bleeding
 Dyspnea prior to exertion
 Dizziness
 Headache
 Chest pain
 Muscle weakness
 Calf pain or swelling (need to rule out thrombophlebitis)
 Preterm labor
 Decreasing fetal movement
 Amniotic fluid leakage
ACOG,2002

25. Maternal advice after exercise
recommendation
 Should aware of uterine contractions
 Less than the fetal movements in 12 hours is an
indication that further investigation at a hospital
is warranted
 No longer suggest the routine counting of fetal
movements in the second half of a woman’s
pregnancy
NICE Guideline, 2004

26. Exercise in postpartum
 Many of the physiologic and morphologic changes of
pregnancy persist 4-6 weeks postpartum.
 Thus, prepregnancy exercise routines should be resumed
gradually based on a woman’s physical capability.
 No known maternal complications are associated with
resumption
 Decreased incidence of postpartum depression and
stress relieving
Hale et al, 1996
Koltyn et al, 1997
ACOG, 1994; ACOG 2002

27. Thank you for your attention