The document discusses the risks and benefits of exercise during pregnancy. It provides an overview of physiological adaptations to exercise during pregnancy and current guidelines from organizations like ACOG. It also outlines recommendations for developing a personalized exercise prescription for pregnant women based on factors like intensity, frequency and type of activity. The summary emphasizes that exercise can have many health benefits for both mother and baby when undertaken safely and within medical guidelines.

1. Exercise in Pregnancy Jennifer Hale, M.D. Valley Baptist Family Practice Residency

2. Objectives Discuss risks and benefits of exercise for both mother and baby Describe physiologic adaptations to exercise during pregnancy Review absolute and relative contraindications to exercise during pregnancy Prescribe an individualized exercise program for a pregnant athlete Practice what we preach !

3. “ We are all athletes…some of us are in training, and some of us are not”

5. Historical Perspective “ The midwives answered Pharaoh, ‘Hebrew women are not like Egyptian women; they are vigorous and give birth before the midwives arrive.’” Exodus 1:19

6. Fun Facts ↑ HDL, ↓ triglycerides ↓ blood pressure Improved endothelial function Improved glycemic control ↓ risk of CAD ↑ longevity ↓ cancer risk ↓ proinflammatory cytokines ↓ oxidative stress Improved psychological well-being

7. Continued… ↑ energy ↓ weight gain ↑ strength/endurance ↓ back pain Improved sleep Improved sense of well-being ↓ risk GDM ↓ risk pre-eclampsia

8. Continued… CDC and ACSM Recommendations: 30-60min moderate-intensity physical activity “on most—preferably all—days of the week” At least 60min to prevent weight gain, increase fitness, achieve full health benefits

9. (Not So) Fun Facts Less than 25% pregnant women exercise regularly 40-60% are completely inactive during pregnancy Pregnancy seen as “confinement” Non-white women 50% less likely to exercise Rest/relaxation seen as more important Most women decrease or stop all exercise while pregnant

10. ACOG Guidelines (1985) Overly conservative HR <140bpm No exercise over moderate intensity No longer than 15min Avoid valsalva (weight lifting) No exercise in supine position after 1 st trimester

11. Where We’ve Come From Zahereiva et al. From 1952-1972 -27% female athletes competing consecutively gave birth between Olympic games -most report feeling ‘more fit’ after childbirth “ They became stronger, had greater stamina and were more balanced in every way after having a child.”

12. Physiologic Adaptations during Pregnancy and Exercise Cardiovascular Pulmonary Thermoregulatory Control Musculoskeletal

13. Cardiovascular Rest ↑ plasma volume ↑ baseline heart rate ↑ cardiac output ↑ stroke volume ↓ systemic vascular resistance Exercise ↓ BP ↓ vagal tone as pregnancy advances Blunted HR response to exercise

14. Continued… ACOG Recommendations: Avoid exercise in supine position after 1 st trimester Avoid prolonged standing HR > 140 now allowed

15. Pulmonary Rest ↑ tidal volume ↑ oxygen uptake ↑ resting oxygen requirements ↑ work of breathing Exercise ↓ oxygen available for exercise ↓ maximum performance SOB with less exertion

16. Continued… ACOG Recommendations : No specific recommendation, except… Exercise intensity should be based on symptoms

17. Thermoregulatory Control Rest ↑ basal metabolic rate ↑ heat production Fetal core body temp 1ºC higher ↑ blood supply to skin Lower sweating threshold Exercise ↑ temp related to exercise intensity ↑ conduction of heat to periphery Moderate exercise ↑ core temp 1.5° first 30min ↑ teratogenic risk?

18. Continued… Clap et al. - 10 recreational joggers - core body temp measured during moderate intensity exercise - pre-pregnancy, 20 and 32wks Results: - increase in core body temp, but less so in pregnancy (1 °C lower) - due to decrease in sweating threshold, etc. - thus NTD not likely in humans

19. Continued… ACOG Recommendations : Avoid hot, humid conditions, high altitudes Wear appropriate clothing Stay hydrated! Innate physiologic protection against hyperthermia

20. Musculoskeletal Rest Center of gravity up and forward ↑ back pain ↑ joint laxity Weight gain Exercise May negatively affect balance ↑ force across hips/knees up to 100% in wt bearing ↑ fall risk? ↑ instability, risk for injury?

21. Continued… ACOG Recommendations : No specific guidelines Adjust activity based on gestational age, symptoms Stretching/strengthening exercises

22. Exercise and Gestational Diabetes Improves glucose tolerance, blunts insulin response # hrs spent in exercise – ↓ risk of GDM - Case control : 155 pts w/ GDM vs. 386 controls First 20 wks — 48% reduction GDM Greatest when combined w/ exercise 1yr prior - ≥ 4.2 hrs/wk mod intensity exercise – ↓ 76% May prevent initiation of insulin

23. Exercise and Pre-eclampsia Reduces risk (40%) - inversely related to time/intensity Sorensen et al. 201 pre-eclamptic vs. 383 controls - “any regular physical activity” first 20 wks 35% - light/mod vs. vigorous 24% vs. 54% - brisk walking ( ≥ 3mi/hr) 30-33% - vigorous exercise year prior 60% - stair climbing (1-4 flights/d) 29%

24. Other Benefits No ↑ risk of miscarriage Possible ↓ risk preterm birth ↓ risk of cesarean section ? Faster recovery post-partum Labor duration ?

25. Effects on Infant Placenta larger, greater surface area Does not change uterine/umbilical blood flow FHR – accelerations, mild decelerations, then baseline Lower birth weight if vigorous exercise 5-6x/wk Children lighter/leaner Score higher on intelligence & oral language tests

26. Current ACOG Guidelines Even more liberal than previous In absence of contraindications, pregnant women can follow ACSM recommendations Avoid supine positions after 1 st trimester No reports that hyperthermia during exercise is teratogenic

28. Exercise Prescription Where to Start: - Gather information for History & Physical Exam - Gestational age - Goals - Grade - “ F I T T”

29. “ F I T T” F requency- “ most days of the week” I ntensity- THR vs. Borg scale T ype- walking/biking/running/swimming T ime- 30-90min/day

30. Borg Scale

31. “ F I T T” F requency- “ most days of the week” I ntensity- THR vs. Borg scale T ype- walking/biking/running/swimming T ime- 30-90min/day

32. Sample 60-90min 30-60min 30min Time Competitive activities Also run/jog dance, tennis Walk, bike, stair, swim, aerobics Type 75-85% MHR RPE- hard 65-85% MHR RPE- mod hard to hard 65-75% MHR RPE- mod hard Intensity 4-6x/wk 3-5x/wk ≥ 3x/wk Frequency Elite Recreational Sedentary

33. Continued… Stretching - static, not ballistic - hold for at least 1min Weight Lifting - 10-15 repetitions - low weight

34. Nutrition Four F’s : F ood ↑ 150cal/day 1 st - 2 nd trimester ↑ 300cal/day 3 rd trimester F luids ↑ 30ml/day 1 lb = 500cc F e (Iron) F olate

35. Contraindications Absolute PIH/Preeclampsia Ruptured membranes Incompetent cervix 2 nd or 3 rd trimester bleeding Multiple gestation Placenta previa after 26wks Heart disease Restrictive Lung disease Premature labor Relative IUGR Cardiac dysrhythmias Severe anemia Chronic bronchitis, heavy smoker Poorly controlled DM, HTN, seizure d/o, thyroid dz Extremes of weight Orthopedic limitations

36. Warning Signs Vaginal bleeding Dyspnea prior to exertion Dizziness or presyncopal symptoms Headache, muscle weakness Chest pain, calf pain or swelling Preterm labor, leakage of fluid Decreased fetal movement

37. Breastfeeding and Exercise Integral role in post-partum weight loss Does NOT reduce milk production Increased lactate levels in breast milk after exercise Breastfeed before exercise!

38. Return to Competition No specific recommendations Guided by symptoms, ability to get back into training Husbands play a big role

39. Summary Pregnancy is a good time to establish healthy lifestyle habits Those adopted during pregnancy could affect a woman’s health for the rest of her life Be aware of contraindications/warning signs Almost all women can safely exercise (or begin an exercise program) during pregnancy

40. QUESTIONS?

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