PA and pregnancy

Question 1

what are the canadian PA guidelines? from which organization?

Answer 1

• adults aged 18-65 years should accumulate at least 150min of mod to vigorous intensity aerobic PA per week, in bouts of 10 minutes or more
• also beneficial to add muscle and bone strengthening activites using major muscle groups at least 2 days a week
• from CSEP: canadian society for exercise physiology

Question 2

what are physical guidelines based on? + Improvement in (4)

Answer 2

• based on the fact that they can decrease bad health outcomes in Canada!
• increase volume of PA leads to increase potential improvement in
• TG
• Blood pressure
• body composition
• high density lipoprotein

Question 3

what are supported and postulated benefits of PA for pregnant women? (9)
low vs mod vs high evidence

Answer 3

LOW
- improves sense of well-being, prenatal anxiety, depression
MODERATE:
- cardiovascular fitness
- low back pain and pelvic girdle pain
- urinary incontinence treatment
- gestational diabetes mellitus
- gestational hypertention and pre-eclampsia
- post-natal depression
HIGH
- gestational weight gain
- urinary incontinence prevention

Question 4

what are supported and postulated benefits of PA for fetus? (5)
low vs mod vs high evidence

Answer 4

LOW:
- miscarriage
- fetus developmental concerns
MODERATE
- gestational age and preterm birth
- birthweight
- APGAR scores
HIGH
- none

Question 5

preeclampsia:
- usually diagnosed when?
- 2 main symptomes
- other symptoms (5 ish)

Answer 5

• after 20 weeks gestation (2nd trimester)
  1. persistent hypertention (140/90 mmHg)
  2. proteinuria (24h urinary protein level >= 0.3g/d)
  OTHER symptoms:
• major organ dysfunction
• thrombocytopenia (low number of platelets)
• elevated liver enzyme activities
• persistent headaches or visual disturbances
• epigastric pain (pain in stomach)

Question 6

what are fetal (3) and maternal risks (6) of preeclampsia

Answer 6

FETAL:
- preterm birth
- intrauterine growth restriction (IUGR)
- death
MATERNAL
- abruption placentae (placental lining separated from uterus)
- renal failure
- pulmonary edema
- cerebral hemorrhage
- stroke
- circulatory collapse

Question 7

what are 5 theories of why preeclampsia could occur?
- all contribute to systemic maternal _______ ________ leading to possible ____________ –> which can lead to preeclampsia

Answer 7

• genetic susceptibility
• predisposing maternal constitutional factors
• immune response
• oxidative stress
• abnormal placental development
• contribute to maternal endothelial dysfunction –> vasoconstriction

Question 8

proposed benefits (3) of exercise on the hypothetical causes of preeclampsi

Answer 8

1. oxidative stress –> exercise could upregulate antioxidants and decrease oxidative stress
2. endothelial dysfunction/maternal constitutional factors –> exercise could reverse endothelial dysfunction
3. abnormal placental development and reduced perfusion –> exercise could enhance placental growth and vascularity

Question 9

1. meta-analysis: what does it show for effect of exercise (mixed, yoga, aerobic) on risk of preeclampsia (odds ratio)?
2. systematic review: exercise prepregnant vs during pregnancy vs both –> effect on preeclampsia

conclusion?

Answer 9

• all 3 types of exercise decrease risk –> overall 0.54 odds ratio
• only prepregnancy, pregnancy and both –> show decreased risk of preeclampsia. one study shown 3.2x increase risk but did at higher intensity and more than canadian guidelines

CONCLUSION: some indications that PA pre-pregnancy and during first 20 wks of pregnancy may reduce risk of preeclampsia

Question 10

what is gestational diabetes mellitus?
- what are the cut-offs for fating plasma glucose vs 1h post 75g OGTT vs 2h post 75g OGTT
- 4 risk factors

Answer 10

• glucose intolerance during pregnancy (could be caused by hormone shift which induces insulin resistance)
• fasting glu > 5.3 mmol/L
• 1h >= 10.6 mmol/L (75g OGTT)
• 2h >= 9.0 mmol/L (75g OGTT)
• previous diagnosis of GDM
• member of high risk population (genetics, ethnicities)
• age >= 35 yo
• BMI >= 30 kg/m^2

Question 11

what does meta-analysis show about OA and risk of GDM?
- prepregnancy
- during
- both

Answer 11

• prepregnancy: not significant but leans toward reduce RR
• during: 1.01 RR = same as no exercise
• both: decrease risk! 0.41 RR

Question 12

what is GWG?
- limit GWG associated with (3)
- how much weight is usually retained after pregnancy?
- what is predictive of that weight?
- what is the primary determinant of retained weight?

Answer 12

• gestational weight gain
  1. decreased risk of gestational diabetes
  2. emergency cesarean delivery
  3. macrosomia, large for gestational age
• 0.9-3.3 kg
• weight gain during first 20 wks = predictive
• GWG is primary determinant of retained weight

Question 13

what do meta-analysis show about exercise and GWG?
- only exercise
- exercise + nutrition
- both

Answer 13

• exercise only = 0.68 OD, significant yay!
• exercise and nutrition = 0.66 OD, sig
• both: 0.68 OD, sig –> no different btw only exercise or exercise and nutrition –> so exercise is super important!

Question 14

what are other postulated risks or concern in pregnancy? (4)
- according to Veisy et al. –> PA can increase frequency of what? –> but had no effect on (5 ish)

Answer 14

• miscarriage, spontaneous abortion, premature labor
• low APGAR scores
• delivery complications
• low birth weight
• PA can increase frequency of vaginal delivery significantly BUT no effect on other maternal and neonatal outcomes:
• 1st, 2nd and 3rd stages of labour
• gestational age at birth
• 1st and 5th minute Apgar score
• umbilical cord pH
• neonatal weight, heigh and head circumference

Question 15

what is the APGAR score? (acronym)
- what do we want to see?

Answer 15

Appearance (blue, mixed, red)
Pulse (no pulse, <100, >100)
Grimace (no, mid, yes)
Activity (not moving, slight, moving)
Respiration (no, weak/slow, strong cry)
- we want to see high score! the unhappier/more reactive the baby, the better!

Question 16

meta-analysis
- PA has effect on type of delivery?
- on delivery complications?
- on incidence of preterm birth?

Answer 16

all have no effect! or very minimal (ie 1 study) that shows decreased risk

Question 17

why did a prospective cohort study find that exercise would increase hazard ratio of miscarriage by 3.7 to 4.7x?

Answer 17

• bc exercise > 419min/week (at 11-14 wk pregnancy) –> 3.7x risk
• bc high impact exercise for 75-268 min/wk) –> 4.7x risk

Question 18

what are the potential risk/explanation/mechanisms that explain adverse pregnancy outcomes of women who work a high physical-exertion demands –> and lead to slower growth? (3)

Answer 18

1. heavy lifting –> increase skeletal muscle action –> increase vasomotor tone to skeletal muscle –> decrease blood flow to placenta + increase blood pressure
2. prolonger standing –> blood pooling in lower limbs –> decrease plasma volume and cardiac output –> decrease blood flow to placenta
3. heavy workload –> increase release of catecholamines –> increase uterine contractility

all 3 might lead to reduced fetal growth rate + alter timing of parturition + increase blood pressure!

Question 19

meta-analysis
1. effect of exercise on birthweight? –> 2 studies
2. effect of exercise on placenta?
3. and placenta/body weight ratio?

Answer 19

1. one meta says decrease birth weight by 200g –> is that a good thing? doesn’t mean the baby is healthy/unhealthy VS another meta (a lot more studies) says no effect of exercise on birth weight
2. no significant effect
3. no significant effect (but trends towards benefiting exercise)

Question 20

cardiovascular responses to exercise
- magnitude of responses affected by (3)
- exercise leads to what CV changes (2 main things ish)

Answer 20

• by length of gestation, exercise mode, intensity
• reduced maximal HR + increased resting HR –> reduced maximal HR reserve
• increased CO, HR and SV at submaximal intensities

Question 21

what happens to CO, mean BP and SVR during normal pregnancy?

Answer 21

• CO increases
• mean BP stays same
• SVR decreases

Question 22

• what are respiratory adaptations of mother during pregnancy? explain
• can be seen at which week of gestation?

Answer 22

mother must be able to get rid of excess CO2 and metabolic byproducts such as heat produced by fetus —> increase sensitivity to CO2 which leads to increase minute ventilation!
- ventilation significantly increases by 7th to 8th week due to increase in tidal volume but no change in breathing frequency
- respiration increases can be noticed after 21 weeks gestation for a given workload

Question 23

what are the changes to minute ventilation, oxygen uptake and basal metabolism during pregnancy?

Answer 23

• very big increase in minute ventilation
• increase in O2 uptake
• increase in basal metabolism (but less than increase in O2)

Question 24

summary of changes during exercise: increase or decrease?
- HR
- SV
- CO
- VT
- core temp
- placental perfusion
- hemoconcentration
- plasma volume
- blood pressure
- absolute energy expenditure for a given workload?

Answer 24

• all increase! except plasma volume: decreases!
• absolute EE –> increase as a result of weight gain

Question 25

explain the graph with quantity and quality of maternal exercise on x-axis and maternal and fetal well-being on y-axis - describe curve/line for mom vs fetus - what is the goal?

Answer 25

MOM: - as exercise increases, very big curve for maternal well-being, like a parabole --> increase, then reaches peak, then decreases - benefits like increased metabolic and cardiopulmonary reserve, promotion of normal glucose tolerance and psychological benefits - if TOO much exercise, can have negative well-being like chronic fatigue and musculo-skeletal injury FETUS: - small benefits (fetal and placental adaptations) as exercise increases but rapidly goes into the negative zones (prematurity, fetal growth retardation, altered fetus dev. fetal death) GOAL: focus on health of both mother and fetus. optimal zone for maternal exercise prescription is the zone where most benefit for fetus, and benefits for mother also (although not at peak of mother benefits, bc that would be bad for fetus)

Question 26

describe canadian guideline for PA throughout pregnancy (6 ish)

Answer 26

1. all women without contraindications should be physically active during pregnancy 2. accumulate 150 min mod-intensity PA/week --> meaningful health benefits + reduction in pregnancy complications 3. PA should be accumulated over minimum of 3 days. but being active every day is encouraged 4. include aerobic and resistance training for greater benefits. + add yoga and gentle stretching 5. pelvic flood muscle training may be performed every day to reduce risk of urinary incontinence 6. avoid supine position (especially if feel light-headed, nausea and unwell in that position)

Question 27

what are absolute and relative contraindications to PA during pregnancy?

Answer 27

ABSOLUTE: - ruptured membranes, unexplained persistent vaginal bleeding - preeclampsia - incompetent cervix, IUGR, high order multiple pregnancy (ie triplets), uncontrolled T1D... RELATIVE: (depends on where they are in pregnancy + intensity of contraindication) - recurrent pregnancy loss, history spontaneous preterm birth, gestational HT, anemia, malnutrition, ED, ...

Question 28

what are safety precautions for prenatal PA? (6)

Answer 28

- avoid excessive heat, especially high humidity - avoid physical contact - avoid scuba diving - avoid high altitude - maintain adequate nutrition and hydration - seek supervision from obstetric care provider if athletic competition or exercise a lot above guidelines ....

Question 29

what are safe exercises when pregnant (5)

Answer 29

- walking - swimming - bicycling - jogging - low-impact aerobics

Question 30

use which scale for RPE during pregnancy? - what number?

Answer 30

Bord's rating of perceived exertion! - 12-14 = somewhat hard --> moderate intensity pregnant women should aim for! vs 6 7: very very light 8 9: somewhat light 10 11: fairly light 12 13: somewhat hard 14 15 hard 16 17: very hard 18 19 very very hard 20

Question 31

describe FITT for previously sedentary pregnant vs active pregnant

Answer 31

SEDENTARY: F: 3d/week I: low-moderate T: 15min gradually increase to 30min sessions T: low impact aerobics (swim, walk, cycle) + resistance training ACTIVE: - F: 4d/wk - I: mod-vigorous - T: >=30min per session - T: low impact aerobics + resistance training

Question 32

what is analogous to the PARQ for pregnancy?

Answer 32

PARmex-X! - also gives recommendation of how you should exercise as a pregnant woman! - HR ranges, RPE, warm-up/cool-down, rate of progression, monitoring intensity...

Question 33

review case study!