Exercise and Pregnancy Flashcards
What are some endocrine changes with pregnancy?
- Gonadotropin
- Progesterone
- Estrogens
What are some cardiovascular system changes during pregnancy?
- Uterine Blood Flow
What are some renal changes during pregnancy?
- Renal Blood Flow
- Glomerular Filtration Rate
What are some Respiration and Acid-Base Balances during pregnancy?
- Increased VE
- Reduced PaCO2/Respiratory Alkalosis
What does increased estrogen during pregnancy do?
cardiovascular
- Decreased peripheral vascular resistance
- Decreased mean arterial pressure
- Activation of the Renin-Angiotensin-Aldosterone System
- Na+ Retention
- Decreased Na+H2O (due to stimulataneous increase ADH and thirst)
- Decreased Osmolatity
- Increased Blood Volume
What does increased Estrogen and progesterone during pregnancy lead to?
- Increased drive to breathe
- Increased Ventilation
- Decreased PCO2
What does a decreased osmotic threshold for thirst and AVP release lead to in pregnancy?
- H2O retention
- Decreased Na:H2O
- Decreased Osmolality
What changes occur to Autonomic control in pregnancy?
- Altered skeletal muscle autonomic acitvity
- Increased Burst Incidence
burst incidence is sympathetic activity / 100 heart beats
Describe the Cardiovagal Baroreflex Gain in pregnacy
Baroreflex control of cardiovascular system reset:
- Reset Downward in pregnant women
- Favoring shorter R-R intervals
- No significant change to SBP
r-r interval shorter = faster HR
Describe the central ventilatory chemoreflex in pregnancy
- Response to hyperoxic hypercapnia in late pregnancy
- Increase in subthreshold VE
- Decrease central chemoreflex ventilatory recruitment threshold for CO2
- Increase in central chemoreflex sensitivity
- Chemical control of breathing altered
Describe the increase in progesterone and estrogen effect on ventilatory control
- Increase in CNS progesterone receptors
- Increase Neutral drive to breathe
- Increase in pulmonary ventilation
What does the increase in pulmonary ventilation caused by the increase in estrogen and progesterone in pregnancy do?
Decreased
- H+ Blood
- Brain extracellular fluid
- Threshold of Chemoreflex
Increased
- Sensitivity of Chemoreflex
What is the hypothesis of ventilatory control during human pregnancy?
Increased Progesterone and Estrogen
- Increase CNS Progesterone Receptor
- Increased Neutral drive to breathe
- Increase ventilation
- Increase PaO2 / Decrease PaCO2
- Decreased H+ blood / Brain extracellular fluid
- Decrease threshold / increase sensitivity of central & peripheral chemoreflex response to CO2
- Increased ventilation
What does the mother transport and exchange with the fetus during pregnancy?
- Glucose
-other Nutrients and Substrates - Hormone Precursors
What does the Fetus exchange and transport with the mother during pregnancy?
- Waste Products (CO2, Heat, and Metabolic Byproducts)
What is affected the most by the increased metabolic demands for exercise?
- The cardiovascular system
What is a major factor for the cardiovascular system being affected by the metabolic demand of exercise?
- The Dissipation of the excess heat generated by exercise
What happens to heat production during pregnancy? Why?
Increases
- Basal metabolic rate increases
What is directly related to the increase in body temperature during exercise?
- The exercise intensity
How fast does the core temperature of non-pregnant women rise during moderate-intensity exercise?
- 1.5C during first 30 minutes
- Plateau’s after another 30 mins
What is critical to heat balance?
- Maintenance of euhydration
- Maintenance of blood volume
How does the cardiovascular system aid in heat balance?
- Conductance of heat from core to periphery
What happens during very high-intensity exercise in regards to core temperature?
- Core temperature continues to rise
What did a 1.5C rise in core temperature during embryogenesis in animal studies cause?
- Major congenital malformations
What did human studies on hyperthermia during pregnancy suggest?
- Excess of 39C during first 45-60 days of gestation may be teratogenic in humans.
What is teratogenic?
- Disruption of the development of the embryo or fetus
During pregnancy, under what conditions should exercise not be conducted?
- Hemodynamically significant heart disease
- Restrictive lung disease
- Incompetent Cervix
- Multiple gestation at risk for premature labour
- Persistent second or third trimester bleeding
- Placenta praevia after 26 weeks gestation
- Premature labour during current pregnancy
- Ruptured membranes
- Pregnancy induced hypertension
During pregnancy, under what conditions should exercise be conducted cautiously?
- Severe Anaemia
- Unevaluated maternal cardiac arrhythmia
- Chronic Bronchitis
- Poorly controlled type 1 diabetes
- Extreme morbid obesity
- Extreme underweight
- History of extremely sedentary lifestyle
- Intrauterine growth restriction in current pregnancy
- Poorly controlled hypertension / pre-eclampsia
- Orthopaedic limitations
- Poorly controlled seizure disorder
- Poorly controlled thyroid disease
- Heavy Smoker
What are some warning signs of terminating exercise while pregnant?
- Vaginal Bleeding
- Dyspnoea Before Exertion
- Dizziness
- Headache
- Chest Pain
- Muscle Weakness
- Calf Pain or Swelling (thrombophlebitis)
- Preterm Labour
- Decreased Fetal Movement
- Amniotic Fluid Leakage
What are some hypothetical risks of exercising while pregnant?
- Blood flow to the uterus leading to fetal hypoxia
- Fetal hyperthermia
- Reduced carbohydrate availability to the fetus
- Possibility of miscarriage
Potential risk of aerobic exercise for the mother during pregnancy?
- Acute hypoglycemia
- Chronic Fatigue
- Musculoskeletal Injury
What are the possible benefits of aerobic exercise for the mother during pregnancy?
- Increased Energy Level
- Reduced CV Stress
- Prevention of Excessive Weight Gain
- Facilitation of Labour
- Faster Recovery from Labour
- Prevention of Lower Back Pain
- Prevention of Gestational Diabetes
What are some hypothetical risks of aerobic exercise for the fetus?
- Acute hypoxia
- Acute hyperthermia
- Reduced Glucose Availability
- Miscarriage in 1st trimester
- Premature Labour
- Altered Fetal Development
- Shortened Gestation
- Reduced Birth Weight
What are the possible benefits of aerobic exercise for the fetus?
- Fewer complications of a difficult labor
What are the current guidelines for physical activity during pregnancy?
- 150min/wk
- > 30 mins exercise on most days if not all days
What are the guidelines for physical activity during pregnancy based on?
- Improved maternal-fetal health outcomes
- Reduced risk of gestational diabetes
- Caesarean sections
- Large for gestational age babies
What are the altitude recommendations for physical activity during pregnancy?
- 1800m for lowlanders
Why are there guidelines for restricting physical activity at altitudes for pregnant individuals?
- Critical reductions in oxygen delivery to the fetus
- increased maternal oxygen demand
What are the current deficits in understanding about physical activity at altitude for pregnant women?
- Physical activity patterns in pregnant women living at altitude
- Physiological responses in pregnant women to physical activity in mountainous regions.
- The linkages between physical activity patterns and pregnancy outcomes in active high-altitude natives.
