Week 6 - Exercise in Special Populations Flashcards
Process of conception
Conception occurs when a sperm penetrates an ovum
- 23 chromosomes of the sperm + 23 chromosomes of the ovum = zygote
- 23rd pair is sex
- 22 pairs autosomal
Sex is determined by the sperm
XX = female; XY = male
The rate of multiple births has doubled in Canada since the 1990s
3/1000 births are multiples
- Identical vs. fraternal
– Identical ⅓ — identical genes, single egg and sperm
– Fraternal ⅔ — 50% shared genes; regular siblings; 2 sperm and ova - Increased maternal age
- Assisted Human Reproduction
– Fertility drugs
– Cryopreservation — IVF labs
– Artificial insemination
Pregnancy
a physical condition in which a woman’s body is nurturing a developing embryo or fetus
Prenatal Development
Prenatal development, or gestation, is the process that transforms a zygote into a newborn
length of pregnancy
40 weeks (±2) or 10 months
1st trimester
weeks 1-12
2nd trimester
weeks 13-24
3rd trimester
weeks 25+
Milestones of prenatal development
No period in human lifespan where more changes occur at a faster rate than the prenatal period
Germinal Stage
first two weeks, including conception to implantation
Conception
Day 1
- Sperm and ovum unite, forming a zygote containing genetic instructions for the development of a new and unique human being.
Implantation
Days 10-14
- The zygote burrows into the lining of the uterus. Specialized cells that will become the placenta, umbilical cord, and embryo are already formed.
NOTE: mom and baby blood NEVER mix due to function of placenta
Embryonic Stage
Weeks 3-8
includes organogenesis
Organogenesis
All the embryo’s organ systems form during the six-week period following implantation
Weeks 9-12
Fingerprints; grasping reflex; facial expressions; swallowing and rhythmic “breathing” of amniotic fluid; urination; genitalia alternating periods of physical activity and rest
Weeks 13-16
Hair follicles; responses to mother’s voice and loud noises; 8 to 12 centimetres long, crown to rump; weighs 25 to 100g
Weeks 17-20
Fetal movements felt by mother; heartbeat detectable with stethoscope; lanugo (hair) covers body; eyes respond to light introduced into the womb; eyebrows; fingernails; 13-17 cm long, crown to rump; weights 140-300g
Weeks 21-24
Vernix (oily substance) protects skin; lungs produce surfactant (vital to respiratory function); viability becomes possible, although most born now do not survive
Weeks 25-28
Recognition of mother’s voice; regular periods of rest and activity; 35-38 cm long, crown to heel; weighs 660-1000g; good chance of survival if born now
Weeks 29-32
Very rapid growth; antibodies acquired from mother; fat deposited under skin; 39-43 cm long, crown to heel; weighs 1.2-1.7 kg; excellent chance of cervical if born now
Weeks 33-36
Movement to head-down position for birth; lungs mature; approx. 44-48 cm long, crown to heel; weighs about 1.9-2.6 kg; virtually 100% chance of survival if born now
Weeks 37+
Full-term status; about 49 cm long, crown to heel; weighs about 3kg
Low birth weight (LBW)
- Newborn weight below 2500g
- Preterm most common
- Small-for-date / small for gestational age
Below 1500g
significantly higher rates of long-term problems;
Smaller size
Lower intelligence scores
Problems in school
Large for Gestational Age
newborn weight above 4000g at birth (9lb, 15 oz)
macrosomic
Implications of LGA
Increased likelihood of chronic disease later in life;
Obesity
CVD
Diabetes
Metabolic syndrome
What is stronger predictor of infant body fat at birth:
Timing of excessive maternal weight gain OR total maternal weight gain?
Timing of excessive maternal weight gain, specifically during the first half of pregnancy, is a stronger predictor of infant body fat at birth than total maternal weight gain!!
Maternal Changes During Pregnancy: Milestones
Musculoskeletal Changes
- Increase force on joints
– From increase in body mass; esp hips and knees. - Increased force may cause discomfort to normal joints and increase damage to arthritic or previously injured joints.
- Ligament laxity → Relaxin → more prone to injuries
- Balance
- Lumbar lordosis → deep curve in lower back
Chronic Hypertension
If high blood pressure develops before 20 weeks of pregnancy or lasts more than 12 weeks after delivery, it’s known as chronic hypertension
Gestational Hypertension
If high blood pressure develops after 20 weeks of pregnancy, it’s known as gestational hypertension
How many women develop gestational hypertension?
~9%
Preeclampsia
a serious condition characterized by increased blood pressure and protein in the urine after 20 weeks of pregnancy (~4%).
- chronic hypertension or gestational hypertension can lead to preeclampsia
- Left untreated, preeclampsia can lead to serious — even fatal — complications for both mother and baby
Risk Factors for Hypertensive Disorders/PE
- Obesity
- Sedentary lifestyle
- History of diabetes
- Family history of hypertension
Gestational Diabetes Mellitus
A condition in which women without previously diagnosed diabetes exhibit high blood glucose levels during pregnancy
- Babies born to mothers with GDM are at increased risk of complications, LGA, primarily growth abnormalities and chemical imbalances such as low blood sugar
How many women develop gestational diabetes?
~10%
Risk Factors for Gestational Diabetes
- Maternal age*
- Family history of diabetes*
- Ethnicity*
- Sedentary lifestyle
- Previous GDM
- Obesity and GDM closely linked
Gestational Weight Gain
Excess gestational weight gain (EGWG) and postpartum weight retention (PPWR) are two primary lifestyle contributors to obesity among women of childbearing age.
- Increased risk of birth complication, cesarean delivery, LGA, SGA, infants.
- If a person is not active during pre-pregnancy, pregnancy and even postpartum is a good time to implement PA routine
how many women are at least 5 kg (11 lbs) heavier 6-18 months PP than before pregnancy?
15-20%
Average pregnancy-related weight gain
1.5-7 lbs (0.5- 3.0 kg)
Appropriate Weight Gain
Where does the weight go?
History of PA during Pregnancy
Prior to 1985 Exercise Guidelines for Pregnant people did not exist – told to REST!!
1985
ACOG suggested heart rate should not go above 140bpm
1994
ACOG Ignored heart rate; Replaced with “common sense” guidelines
2002
ACOG Ignored heart rate; Replaced with exercise on all days of week!!
PARmed-X for Pregnancy
(Physical activity readiness, medical pre-screening & exercise prescription) - written for physician/midwife or health care professional to increase communication
CSEP & Health Canada (1996; Revised 2002; 2011; 2013)
2003
Canadian guidelines for active living during pregnancy – Joint SOGC/CSEP Clinical Practice Guideline
Canadian Physical Activity Guidelines during Pregnancy
2019
- Published article in BJSM → Journal of Sport and Exercise Medicine
Get Active Pregnancy Questionnaire (replaces PARmed-X)
2020
Medical Screening
Get Active Pregnancy Questionnaire → 2 page document
Prescreening tool → if they answer yes to any Q they need to take followup questionnaire to their healthcare provider to go over some things
Canadian Physical Activity Guidelines during Pregnancy Recommendation 1
_all_ women without contraindication should be physically active throughout pregnancy
- Strong recommendation, moderate-quality evidence
- subgroups:
– Women who were previously inactive.
– Women diagnosed with gestational diabetes mellitus.
– Women categorised as overweight or obese (pre-pregnancy body mass index ≥25 kg/m2)
Canadian Physical Activity Guidelines during Pregnancy Recommendation 2
pregnant women should accumulate at least 150 minutes of moderate-intensity physical activity each week to achieve clinically meaningful health benefits and reductions in pregnancy complications
Canadian Physical Activity Guidelines during Pregnancy Recommendation 3
physical activity should be accumulated over a minimum of three days per week; however, being active every day is encouraged
Canadian Physical Activity Guidelines during Pregnancy Recommendation 4
pregnant women should incorporate a variety of aerobic and resistance training activities to achieve greater benefits
- adding yoga and/or gentle stretching may also be beneficial
Canadian Physical Activity Guidelines during Pregnancy Recommendation 5
pelvic floor muscle training (ie. kegel exercises) may be performed on a daily basis to reduce the risk of urinary incontinence
- instruction in proper technique is recommended to obtain optimal benefits
Canadian Physical Activity Guidelines during Pregnancy Recommendation 6
pregnant women who experience light-headedness, nausea or feel unwell when they exercise flat on their back should modify their exercise position to avoid the supine position
Moderate Intensity PA
Intense enough to increase HR; a person can talk but not sing during activity
e.g. brisk walking, water aerobics, stationary cycling (moderate effort), resistance training, carrying moderate loads, household chores (e.g. gardening, washing windows).
3 Ways to Monitor Intensity
Maternal Heart rate – pregnancy-specific target heart rate zones
“Talk test” – maintain a conversation during PA and should reduce intensity if not possible
Rate of Perceived Exertion (Borg Scale ~7/10 effort)
Heart Rate Ranges for Pregnant Women