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Carrie A. Jaworski, MD, FAAFP, FACSMDivision & Fellowship DirectorPrimary Care Sports Medicine
University of Chicago/NorthShoreUniversity HealthSystem
Objectives Review current guidelines and theoretical concerns for
exercise in pregnancy
Gain insight into issues commonly encountered by pregnant & postpartum runners/endurance athletes
Learn return to running plan in the postpartum period
Exercise in Pregnancy In the US, 42% of
women do some exercise during pregnancy
21% continue for more than 2/3 of the pregnancy
Women with children are 1.67x more likely to quit an exercise program
Our role as healthcare providers: Help our patients maintain maternal fitness levels, while minimizing risk to fetus
Historical Perspectives
In 1950’s, women were allowed to walk one mile daily, preferably broken up into several sessions
Historical Perspectives In 1985, ACOG endorsed
safety of most aerobic exercise
Strict limitations
Duration (15 minutes)
Maximum heart rate (140)
Historical Perspectives In 1994, ACOG releases
statement that “during pregnancy, women can continue to exercise and derive health benefits even from mild to moderate exercise routines.”
Cautious approval ACOG Technical Bulletin No. 189, Feb. 1994
2002 Guidelines “In the absence of either medical or obstetrical
complications, 30 minutes or more of moderate exercise on most, if not all, days of the week is recommended for pregnant women.”
First formal recommendation to include exercise during pregnancy
ACOG Committee Opinion No. 267, Jan. 2002
Current Guidelines - 2015Regular physical activity in all
phases of life, including pregnancy, promotes health benefits. Pregnancy is an ideal time for maintaining or adopting a healthy lifestyle and the American College of Obstetricians and Gynecologists makes the following recommendations…
ACOG Committee Opinion No. 650, Dec. 2015
The fine print… 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.
One 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.
Studying Exercise in Pregnancy IRB approval is difficult (vulnerable population)
Randomized controlled trials are difficult Double blinding is impossible!
Exercise intervention must be defined – type, duration, intensity
Recommendations are often based on retrospective and case studies or on assumptions based on what we know about the effects of exercise on the non-pregnant woman and the physiologic adaptations of pregnancy
Adaptations to Pregnancy
♦ Increased vascular elasticity
♦ Expanded plasma volume
♦ Increased heart chamber size, stroke volume and heart rate
♦ Increased blood flow to the skin, kidneys and reproductive tissues
Pregnancy Exercise
♦ Increased blood volume
♦ Increased heart chamber size and stroke volume
♦ Increased blood flow to the skin and muscles
♦ Increased ability to deliver oxygen and nutrients to tissues
Cardiovascular System
Physiology- Maternal Adaptations Cardiovascular:
-Cardiac output increases by up to 50%
-Resting heart rate rise of 15 bpm
-Blood volume increases ~45%
-Stroke volume increases ~30%
-Mean arterial blood pressure falls ~10 torr
-Regional blood flow changes
Adaptations to Pregnancy
♦ Anatomy of the chest wall changes to allow for increased oxygen transport and use
Lung compliance increases as airway resistance decreases
♦ Tidal volume, minute ventilation and oxygen consumption increases(Increased resting O2
requirement)
Pregnancy Exercise
♦ No long term changes in most aspects of breathing and lung function
♦ Improves gas transfer and oxygen availability and usage at the level of microcirculation and the cell
Pulmonary System
Proposed physiologic concerns“Risk of fetal hypoxia as exercising muscle diverts
blood flow from placenta”
~50% decrease in splanchnic blood flow
Not True
Compensatory mechanisms Increased maternal hematocrit & oxygen extraction
prevent impairment Maternal exercise increases size and O2 exchanging
capacity of placenta in 1st two trimesters
Effect of exercise on placental volume
Rizk AJOG1992
Proposed physiologic concerns Supine position = 9% decrease in cardiac
output Avoid prolonged supine position after 1st trimester
High altitude = Decreased uterine blood flow Caution at > 8,250 feet until acclimated
Additional Maternal Adaptations Metabolic:
-Increased metabolic rate
-Utilize CHO at greater rate at rest and with
exercise and lower glycogen reserve
-Reduced peripheral insulin sensitivity and
hyperinsulinemia
Proposed physiologic concerns“Risk of hypoglycemia”
Decreased VO2 max secondary toincreased fetal oxygen demand andlimited diaphragm expansion = dependenceon carbohydrates as primary fuel= decrease in plasma glucose concentration
Risk with prolonged or strenuous exercise Avoid by increased intake of complex carbohydrates
Maternal Adaptations Thermoregulatory control:
Increased basal metabolic rate and heat production in pregnancy
Fetal temp 1.0°C higher than maternal oral temp
Maternal core temp decreases in pregnancy ~0.3°C in 1st
trimester
Proposed physiologic concerns
“Exercise and pregnancy both increase metabolic rate”
Maternal temperatures >102.6 F are potentially teratogenic in 1st trimester
-Core temp rises 1.5°C in non-pregnant exercising women and then reaches steady state
-Limited human studies, none with exercise (JAMA, 1992) Increased minute ventilation and skin
blood flow augment heat dissipation
Adaptations to Pregnancy
♦ Increase in body weight
♦ Change in the center of gravity
♦ Relaxin causes increased joint and ligament laxity
♦ Forces across joints double
Increased anterior pelvic tilt
Separation of abdominal muscles
Widening of SI joint and pubic symphysis
Dissipate heat more rapidly
Relatively insulin resistant
PregnancyExercise
♦ Increases muscle mass and coordination
♦ Improves ligamentous tensile strength and bone density
♦ Increased insulin sensitivity
♦ Increased ability to dissipate heat
Musculoskeletal System
Biomechanics - Pregnant Runners 20 healthy women walked on a treadmill while wearing
a custom made pseudo-pregnancy sac (1 kg) under 3 load conditions:
sac-only condition
10-lb condition (4.535 kg added anteriorly)
20-lb condition (9.07 kg added anteriorly)
Kinematic changes at the knee, hip, pelvis, and trunk in the sagittal and frontal planes
Changes may suggest that women modify gait biomechanics to reduce the effect of added load
Physiologic Concerns
Conditions seen in pregnancy– Low back pain
– Symphysis pubis pain
– Tenosynovitis of the Wrist
– Patellofemoral pain
– Leg cramps
Theoretical risks:
- Increased risk of sprains and strains
- Balance problems
No conclusive evidence of increased rates of above with exercise
Musculoskeletal issues Low back pain
Lumbosacral strain, spasm Sacroiliac dysfunction
Avoid high heels Stability ball exercises Physical therapy
Wrist tenosynovitis Carpal Tunnel DeQuervain’s
Wrist splints Therapy (OT,PT) Injection
Musculoskeletal issues Pubic symphysis pain
Pelvic stabilization exercises
Injection
Patellofemoral Syndrome Quad strengthening,
hamstring stretching
Bracing
Physical Therapy
Musculoskeletal issues Leg cramps
More related to dehydration/sodium deficits than potassium
Possible acupressure point ???
“Exercise behaviors and health conditions of runners after childbirth”
Cross-sectional survey study of 725 runners (Blyholder, 2016)
72% of regular runners continued in pregnancy
38% continued into the 3rd trimester
50% returned to running within 6 weeks of delivery
Survey Characteristics Types of exercise before
and during pregnancy
Occurrence of antenatal and postpartum MSK pain
Stress urinary incontinence
Perception of diastasisrecti
Findings Nearly 35% had MSK pain upon returning to running
91% had pain in Lumbopelvic region: low back, pelvis and/or hips
Most had h/o antenatal msk pain
Weight training during pregnancy had significantly lower risk of msk pain
Also had less stress incontinence
Diastasis less in primips vs multiparous runners
Proven Benefits of Exercise in Pregnancy
Physical:1. Maintain/improve
maternal fitness2. Control excess
weight gain, Diabetes, BP
3. Improve appearance,posture, & sleep
4. Increase energy5. Decrease LBP,
varicose veins, &water retention
Proven Benefits of Exercise in Pregnancy
Psychological:
1. Improved self-image
2. Improved sense of
control
3. Relief of tension
Mother’s Health: Discomforts of Pregnancy
Wallace, et al.
31 exercising pregnant women compared to 22 non-exercising pregnant women
↑ Self Esteem
↓ Fatigue
↓ varicosities
↓ peripheral edema
Polman, et al.
66 subjects randomized to aqua class, gym studio class, craft class or control
↑ Mood in exercising women
Mother’s Health: Back Pain Back Pain is extremely
common in pregnancy
Mota, et al: n=71 67% incidence
Prevented women from performing usual activities – 57.7%
Worsened in later pregnancy – 77.5%
Received no treatment – 93%
Treatments include: PT, support belts, pain medication, mobility aids
Mother’s Health: Back Pain
Haakstad, et al.
105 Primigravid previously sedentary women
40 min endurance + 20 min strength + stretching
No difference in pelvic girdle/ back pain
Kluge, et al.
26 v 24 controls with back pain – 10 week exercise program
Improved pain intensity and functional ability in intervention group
Mother’s Health: Blood PressureSorensen, et al.
201 preeclamptic & 383 normotensive pregnant women
↓ Risk of preeclampsia by 35%
Decreases in the risk of preeclampsia proportionate to the intensity of the activity and energy expended
Mother’s Health: DiabetesMeta-Analysis, 2015
10 studies analyzing 3,401 participants randomized to exercise intervention versus controls
25% reduced risk in the exercise group versus control group
Suggest physical activity is slightly protective. More studies needed for type, timing, duration and compliance to form guidelines
Russo, et al. Obstet Gynecol. 2015
Mother’s Health: Weight Gain
Elliott-Sale KJ et al. Pregnancy Htn, 2014
Literature Review studies with exercise weight
intervention vs. control between 1990-2013
354 studies
5 studies
- Non-randomized- Retrospective- Combined interventions- Not designed to influence weight
- 3 pregnancy- 2 postpartum
2/3 showed reduced weight
gain
More weight loss than controls
Pregnancy OutcomesLabor Decreased rate of medical
interventions
Decreased need for pain medications
Shorter labor on average
?
Kardel, et al.-Measured VO2max in 40 nullips at 35-37 weeks-Measured time between 3cm dilation and delivery-VO2max inversely related to labor time
Effects On The Fetus
Birth weight:
-Inconsistent data
-More dependent on caloric intake
-Participation in moderate to vigorous activity throughout pregnancy may enhance birth weight, while severe regimens can = lighteroffspring (Pivarnik,MSSE,92)
Effects On The Fetus
Gestation length:
-Catecholamine release with exercise raises
concerns regarding preterm labor
-NE increases strength & frequency of uterine
contractions
-Epinephrine inhibits uterine activity
-Meta-analysis (Pivarnik,MSSE, 1992) = no difference in length of gestation
Impact On Exercise Performance Greatest on weight-bearing activities
-Associated with increasing pelvic pressure
-Progressive decline is natural Elite athlete, Sue Olsen ran a 4 hour marathon when 8
1/2 months pregnant
No effect seen with nonweight-bearing exercise
Nutritional Concerns Pregnancy requires additional 300 kcal/day
Must increase intake further based on activity level
Metabolic “cost” of exercise increases throughout pregnancy as woman gets heavier
Need to monitor athletes for weight loss or lack of weight gain
Nutritional Concerns Weight gain of < 1 kg/month in second and third
trimester unacceptable
Adequate water intake
Folic acid, calcium, protein
How do I start?When should I stop?
• Hemodynamically significant heart disease• Restrictive lung disease• Incompetent cervix or cerclage• Multiple gestation at risk of premature labor• Persistent second- or third-trimester bleeding• Placenta previa after 26 weeks of gestation• Premature labor during the current pregnancy• Ruptured membranes• Preeclampsia or pregnancy-induced
hypertension• Severe anemia
Absolute Contraindications to Aerobic Exercise
ACOG Committee Opinion No. 650, Dec. 2015
Relative Contraindications• Anemia• Unevaluated maternal cardiac arrhythmia• Chronic bronchitis• Poorly controlled type 1 diabetes• Extreme morbid obesity• Extreme underweight (BMI less than 12)• History of extremely sedentary lifestyle• Intrauterine growth restriction in current pregnancy• Poorly controlled hypertension• Orthopedic limitations• Poorly controlled seizure disorder• Poorly controlled hyperthyroidism• Heavy smoker ACOG Committee Opinion No. 650, Dec. 2015
ACOG Guidelines On Exercise During Pregnancy
Regular activity preferable to intermittent (3 times/week)
Augment heat dissipation in the 1st trimester via adequate hydration, appropriate clothing, and optimal environmental surroundings
Morphologic changes are a relative contraindication to exercises that require balance, especially in 3rd trimester
ACOG Guidelines on Exercise During Pregnancy (Cont.)
Avoid any exercise with potential for abdominal trauma
Women should be aware of the decreased oxygen available for aerobic exercise and modify their workouts based on maternal symptoms
ACOG Guidelines on Exercise During Pregnancy (Cont.)
Avoid exercise in the supine position after the 1st trimester
Avoid prolonged periods of motionless standing
ACOG Guidelines on Exercise During Pregnancy (Cont.)
Pregnancy requires an additional 300 kcal/day. Therefore, ensure adequate nutrition while exercising
Many of the physiologic and morphologic changes of pregnancy persist 4-6 weeks postpartum. Thus, PREPREGNANCY exercise routines should be resumed gradually
Exercise Prescription Individualize
Emphasis on safety
Monitor maternal symptoms
No evidence that any aerobic or anaerobic activity should be avoided (except scuba)
Exercise Prescription Sedentary women:
-Frequency = Minimum of 3x/week
-Intensity = 65-75% max HR or
perceived exertion = moderately
hard
-Type = Low-impact (walking, swimming)
-Time/Duration = 30 minutes as a goal
Exercise Prescription Regular exercisers :
-Frequency = 3-5x/week
-Intensity = 65-80% max / Perceived Exertion=
moderately hard to hard
-Type = Low-impact and any prior activities
-Time/Duration = 30-60 minutes, more as tolerated
Exercise Prescription Elite athletes
-Frequency = minimum of 4-6x/week
-Intensity = 75-80% max/ PE=hard
-Type = Same as others plus some competitive activities depending on gestational age
-Time/Duration = 60-90 minutes, increase as tolerated
Postpartum Issues
When to start/resume exercise?
Risks/benefits?
What to do?
Postpartum Exercise Benefits
Increased cardiovascular fitness
Facilitate weight loss
Increase mood
Decrease anxiety & depression
More energy after exercise
Possible Concerns Lactation
Bleeding
Incontinence
Diastasis recti abdominus
Lactation and Exercise Both physiologically demanding
Older studies done on cows!
More recent research has shown that frequent, sustained, moderate to high intensity running during lactation did not impair the quantity or quality of human breast milk No increased lactic acid
No change in volume if hydrated
Keep calories at or above 1,500kcal/day
Study by Carey and Quinn showed quicker return to pre-pregnancy weight
Lactation and Exercise
No effect on milk acceptance
No effect on growth of infant
No effect on milk production
Positive effects for mom
Lactation – Stress Fracture Risk? Pregnancy and lactation may cause transient decrease
in bone mineral density and rarely osteoporosis It is unclear if women compensate for this after they stop
nursing
Significant axial bone loss after 3-4 months of lactation Caused by prolonged estrogen deficiency
Calcium losses of > 200-400mg/day
Amenorrhea is common with lactation Possible energy imbalance
Possible increased risk similar to female athlete triad
Bone Loss and Breastfeeding
Exercise can enhance bone mineralization
Spinal bone mineral density recovered once menses resumed
Increased Bleeding? Old recommendations instruct no lifting, stairs or
muscle conditioning exercises
Thought to increase bleeding
False!
Incontinence and Exercise 30-60% of pregnant women
15% of women have stress incontinence 3 months after delivery
Initiate Kegels during pregnancy
Exercise, esp weight training, may decrease risk
Kegels Routine 8-12 maximum pelvic floor
muscle contractions
2x/day at least 3x/week
Hold 6-8 seconds and add 3-4 fast contractions at end of each max contraction
Sometimes Kegels can backfire! Hypertonicity of pelvic floor is a separate issue often seen
Diastasis Recti Split of rectus abdominus along linea alba
66% in 3rd trimester
53% immediate postpartum
36% 5-7 weeks postpartum
More likely to be absent in those who exercised prior to & during pregnancy
Abdominal Exercises Postpartum Use caution as decreased ability of abs to stabilize
pelvis during pregnancy and initial postpartum period
Avoid high torque exercises to maintain pelvic stability
Weight Loss Average women retains 0.5 -1 kg body mass gained
during each subsequent pregnancy
Those who gain after delivery have worse prognosis
Weight loss > 1.5 kg/week not recommended in lactating women
Recommendations For normal vaginal deliveries, may resume mild
program of walking, pelvic floor exercises and stretching immediately
C-sections or complicated deliveries, medical clearance at 6 week checkup
Recommendations Aerobic and muscle
conditioning activities
Use FITT principle.
Start once bleeding is minimal
Perceived exertion
Increase as tolerated, avoid fatigue
Include baby in routine!
Thank you!