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Exercise During Pregnancy. Antoin M. Alexander Maj USAF MC Family Medicine Sports Fellow Adopted from Dr. Fred Brennan. Case. 24 y.o. G1P0 presents at 9 wks EGA for 1 st obstetrical visit Competes routinely in triathlons and road races
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Exercise During Pregnancy Antoin M. Alexander Maj USAF MC Family Medicine Sports Fellow Adopted from Dr. Fred Brennan
Case • 24 y.o. G1P0 presents at 9 wks EGA for 1st obstetrical visit • Competes routinely in triathlons and road races • Curious about the benefits & risk of continuing to train & possibly competing while pregnant • Will her performance suffer? • Will she put her baby at risk? • Can she exercise & breastfeed in the future?
Overview • Physiology of Exercise and Pregnancy • Risks and Benefits • Guidelines for Exercise in Pregnancy • The Pregnant Athlete • Injury Patterns • College athlete
Useful References • ACOG Committee. Opinion no. 267: exercise during pregnancy and the postpartum period. Obstet Gynecol 2002;99:171–3 • Artal R. Exercise during pregnancy. Safe and beneficial for most. Phys and Sports Med 1999;27:51–60
Useful References • Kelly AK. Practical exercise advice during pregnancy. Guidelines for active and inactive women. Phys and Sports Med June 2005;33(6) • Davies GA. Joint SOGC/CSEP clinical practice guideline: exercise in pregnancy and the postpartum period.Can J Appl Physiol 2003; 28(3): 330-41 • Morris SN. Exercise during pregnancy: a critical appraisal of the literature. J Reprod Med 2005; 50(3):181-8
Physiologic Adaptations to Pregnancy & Interactions with Exercise
Physiology Overview • Significant physiologic changes occur in pregnancy • Objective data on the impact of exercise on the mother, fetus, and course of pregnancy are limited • Theoretical concerns must be understood to allow physicians to advise women who wish to exercise in pregnancy
Fetal Response To Exercise • 45 healthy pregnany woman studied • 15 nonexercisers, 15 regularly active,15 highly active • Tested 28- 33 weeks gestation • Treadmil #1 to volitional fatigue • Treadmill #2 to 40-59% HR reserve for 30 min • Treadmill #2 to 60-84% HR reserve for 30 min • Measure Umbilical artery Doppler, FHR tracing, biophysical profile All doppler similar pre and post exercise Post exercise FHR tracing reactive < 20 minutes BPP scores all reassuring ObstetGynecol 2012; 119 (3) : 603-10
Cardiovascular • Both exercise and pregnancy increase: • Heart rate • Stroke volume • Cardiac output • Theoretical risk: Competing effects on regional blood flow distribution • Exercise decreases splanchnic blood flow • Doppler US not shown changes in uterine or umbilical artery flow • Both glucose and oxygen delivery to placental site is reduced
Cardiovascular II • Women who perform regular weight bearing exercise • Augment pregnancy associated increases in plasma volume • Increase placental volume • Increase cardiac output • What does this suggest? • Increased rate of placental blood flow at rest • Increase in 24 h glucose & oxygen delivery
Substrate Delivery & Utilization • Non-pregnant athlete • Wt-bearing exercise increases glucose oxidation • Sympathetic response mobilizes glucose stores & stimulates gluconeogenesis • Result: rise in glucose levels for at least the first hour • Pregnant athlete • Sympathetic response blunted • Glucose oxidation & lipogenesis are increased • Result: fall in glucose levels during & after exercise
Oxygen Delivery • Pre-pregnancy sustained exercise • h oxygen delivery to muscles & skin • i oxygen delivery to most viscera • During pregnancy oxygen delivery during exercise appears to be maintained by • Maternal hemoconcentration • Improved perfusion at the placental interphase • Conclusion: No evidence for compromised O2 delivery
Pulmonary • Both exercise and pregnancy increase • Minute ventilation • Oxygen consumption • During pregnancy • Resting energy expenditure is increased • Augmented work of breathing during exercise • Result: exercise requires higher VO2 (oxygen uptake) compared with that required in a nonpregnancy state • VO2 max decreases because body weight increases with pregnancy
Thermoregulatory • Both exercise and pregnancy increase • Metabolic rate • Increased heat production • Theoretical concerns: • Elevation in maternal core temperature due to exercise could reduce fetal heat dissipation • Possible teratogenic effect at temp>102.6 • Healthy, fit pregnant women have been shown to tolerate thermal stress
Changing Thermal Response to Endurance Exercise in Pregnancy • 18 well-trained recreational athletes • 20 minutes of cycling at room temperature & 60-65% VO2 max • Maximum core temperature achieved during cycling decreased throughout gestation • Appear to be related to a increased vasodilation & increased sweating Am J Obstet Gynecol. 1991; 165;: 1684-9.
Neuroendocrine • Exercise increases circulating levels of • Norepinephrine • Epinephrine • Theoretical concerns: excess catecholamines and prostanglandins will result in contractions & preterm labor • Cochran review 2010 of 14 trials- 1014 women • No statistically significant change in gestation at delivery
Mechanical Effects • Altered center of gravity • growing breast, uterus and fetus • increased lumbar lordosis • Increased risk of fall • Increased joint laxity • Theoretic increased risk for strains/sprains
Risks • Theoretical risks: • Hypoxemia/Hypoglycemia • Fetal teratogenesis • Preterm labor • Low birth weights • Sprains/strains • Negative outcomes have not been identified: • SAB • Pregnancy complications • PTL/preterm birth • Altered birth weight • Higher injury rates
Sour Milk? • Neither quantity nor quality of breast milk produced appears to be affected by moderate exercise
Benefits • Improved cardiovascular fitness • Control of maternal weight gain • Reduced subjective discomforts of pregnancy • Swelling, leg cramps, fatigue, SOB • Positive influence of labor & delivery (Clapp et al) • Decreased risk of operative or assisted deliveries • Shorter active labor • Increased fetal tolerance of labor • Possible reduced risk of preeclampsia, GDM
Course of Labor after Endurance Exercise in Pregnancy Am J Obstet Gynecol 163: 1799-1805, 1990.
Psychological Well-Being • Improved mood • Decreased stress • Improved self-image • Increased sense of control and relief of tension Semin Perinatol 20: 70-76, 1996.
Postpartum Well-Being • Improved weight loss • Improved psychological well-being • No adverse impact on breastfeeding.
Neonatal & Childhood Benefits • Clapp JF: Morphometric and neurodevelopment outcomes at age 5 years of offspring of women who continued to exercise regularly throughout pregnancy. • Less body fat at birth and 5 yrs • Similar motor, integrative & academic readiness as control groups • Higher scores on Wechsler scales and tests of oral language skills. J. Pediatr 129: 856-863, 1996.
Preventing & Treating GDM • Exercise may be beneficial in the primary prevention of GDM, especially in morbidly obese women (BMI > 33) • Resistance training may reduce need for insulin therapy in overweight women (BMI > 25) • ADA endorsed exercise as helpful adjunctive therapy with GDM when euglycemia is not achieved by diet alone.
Guidelines for Exercise in Pregnancy • ACOG in evolution • 1985: HR <140 BPM with maximum duration of exercise = 15 minutes • 1994: Less cautious and began to stress the health benefits of exercise • 2002: 30 minutes or more of moderate exercise a day recommended • SOGC/CSEP • 2003: All women without contraindications should participate in aerobic & strength-conditioning exercise.
ACOG 2002 • Recognition that regular exercise is beneficial to even pregnant women and should be encouraged. • All women should be evaluated clinically before recommendations made. Obstet Gynecol 2002; 99: 171-173.
Absolute Contraindications • Hemodynamically significant heart disease • Restrictive lung disease • Incompetent cervix/cerclage • Multiple gestation at risk for premature labor • Persistent second- or third-trimester bleeding • Placenta previa after 26 weeks • Premature labor during current pregnancy • Ruptured membranes • Preeclampsia/pregnancy induced hypertension Obstet Gynecol 2002; 99: 171-173
Severe anemia Unevaluated maternal cardiac arrhythmia Chronic bronchitis Poorly controlled type 1 diabetes Extreme morbid obesity Extreme underweight (BMI < 12) Heavy smoker History of extremely sedentary lifestyle IUGR in current pregnancy Poorly controlled hypertension Orthopedic limitations Poorly controlled seizure disorder Poorly controlled hyperthyroidism Relative Contraindications Obstet Gynecol 2002; 99: 171-173
ACOG 2002 • Acknowledges the potential of exercise to prevent & treat gestational diabetes mellitus • Recommends avoiding exercise involving both • the supine position “as much as possible” • prolonged periods of motionless standing • Notes that strenuous activity has not been linked to poor fetal growth or outcomes Obstet Gynecol 2002; 99: 171-173
ACOG & Safety • Safety of each sport determined by the “specific movements required by that sport.” • Scuba diving is contraindicated • Exertion above 6000 feet carries risks. • Hyperthermia associated with exercise has not be shown to be teratogenic Obstet Gynecol 2002; 99: 171-173
Contact sports with risk of abdominal trauma Hockey Basketball Soccer High Risk Sports with risk of both falls and trauma Gymnastics Horseback riding Downhill Skiing Vigorous racquet sport Higher Risk Activities Obstet Gynecol 2002; 99: 171-173
Warning Signs to Terminate Exercise • Vaginal bleeding • Dyspnea prior to exertion • Dizziness • Headache • Chest pain • Muscle weakness • Calf pain or swelling • Preterm labor • Decreased fetal movement • Amniotic fluid leakage Obstet Gynecol 2002; 99: 171-173
Postpartum Exercise • “Prepregancy exercise routines may be resumed gradually as soon as it is physically and medically safe.” • No adverse effects noted for even rapid return to activity. • Moderate weight reduction while nursing does not compromise infant weight gain. • Associated with decreased incidence of postpartum depression. Obstet Gynecol 2002; 99: 171-173
Advising the Pregnant Athlete • Will her athletic performance suffer? • Will she lose a significant amount of aerobic fitness? • Will her submaximal performance be affected? • Can she safely continue resistance exercises? • Should she stop competing? • How soon can she return to competition? • Are breastfeeding and competitive athletics mutually exclusive?
Orthopedic Concerns • No injury pattern has been definitely associated with exercise in pregnancy • Increased joint laxity + weight gain = increased risk of joint discomfort
Common Orthopedic Conditions • Low back pain
Common Orthopedic Conditions • Low back pain • Pelvic/hip pain
Common Orthopedic Conditions • Low back pain • Pelvic/hip pain • Pubic pain
Common Orthopedic Conditions • Low back pain • Pelvic/hip pain • Pubic pain • Knee pain • Leg cramps
Common Orthopedic Conditions • Low back pain • Pelvic/hip pain • Pubic pain • Knee pain • Leg cramps • Carpal Tunnel Syndrome • DeQuervain’s Tenosynovitis
Exercise Prescription • Goal: Maintain maternal fitness levels and minimize risk to fetus. • Points to consider • Current fitness level • Goals for exercise • Job/occupational requirements • Gestational age • Intensity: Perceived exertion • Safety is key!
Nutrition • Energy intake needs to be sufficient to meet energy expenditure and promote weight gain. • Gestational weight gain (total & rate) good indicator of adequate nutrition • Quality of diet should be assessed periodically
Practical Advice • Begin discussions at the first visit • Structure each regimen individually • safe upper limit of exercise will be dictated by a women’s fitness status prior to entering pregnancy • Encourage rest-activity cycles • Promote exercise as relaxation