Physiology Of Pregnancy

Question 1

How long is the Average Human Pregancy?

Answer 1

40 weeks - (9 months)

Question 2

How many trimesters in pregnancy?

Answer 2

• Three Trimesters
  
  • first (<12 weeks)
  • second (12 weeks to end week 26)
  • third (27 weeks – birth)

Question 3

When is the First Trimester? (Pregancy)

Answer 3

first (<12 weeks)

Question 4

When is the Second Trimester? (Pregancy)

Answer 4

second (12 weeks to end week 26)

Question 5

When is the Third Trimester? (Pregancy)

Answer 5

third (27 weeks – birth)

Question 6

During Pregnancy, there are many … changes – ie. not … changes - that take place to support the to support the needs of a … …

Answer 6

• During Pregnancy, there are many physiological changes – ie. not pathological changes - that take place to support the to support the needs of a growing fetus
  
  • Supplying a baby with enough nutrients (O2, glucose, amino acids) for growth, development, production of amniotic fluid
  • Managing increased waste production – eg. CO2, nitrogen compounds
  • Change in hormones to support pregnancy and prepare
  • for delivery
  • Anatomical changes to accommodate the growing fetus and
  • preparing for labour
  • Manage the stresses of delivery and potential haemorrhage
  • Postnatal Recovery and Breastfeeding

Question 7

Physiological Changes During Pregnancy:

• Supplying a baby with enough … (O2, glucose, amino acids) for growth, development, production of … fluid
• Managing increased … production – eg. CO2, nitrogen compounds
• Change in … to support pregnancy and prepare
• for delivery
• … changes to accommodate the growing fetus and
• preparing for labour
• Manage the … of delivery and potential …
• … Recovery and B…

Answer 7

• Supplying a baby with enough nutrients (O2, glucose, amino acids) for growth, development, production of amniotic fluid
• Managing increased waste production – eg. CO2, nitrogen compounds
• Change in hormones to support pregnancy and prepare
• for delivery
• Anatomical changes to accommodate the growing fetus and
• preparing for labour
• Manage the stresses of delivery and potential haemorrhage
• Postnatal Recovery and Breastfeeding

Question 8

Which systems undergo some form of change during Pregnancy?

Answer 8

• All of them!!
  
  • Endocrine
  • Cardiovascular
  • Respiratory
  • Haematocological
  • Musculoskeletal/Dermatological

Question 9

Endocrine Changes During Pregnancy

• 3 MAIN HORMONES INVOLVED IN PREGNANCY that you need to know about
  
  • … – dramatic rise in the first days-weeks - released from the corpus luteum initially, then by placenta
  • … - keeps the state of quiescence
  • … – breast growth, areolar enlargement
• Other hormone changes include …, … and …

Answer 9

• 3 MAIN HORMONES INVOLVED IN PREGNANCY that you need to know about
  
  • BHCG – dramatic rise in the first days-weeks - released from the corpus luteum initially, then by placenta
  • Pro-gest-erone eg.pro-gestation - keeps the state of quiescence
  • Oestrogen – breast growth, areolar enlargement
• Other hormone changes include relaxin, inhibin and TSH

Question 10

BHCG and Pregnancy

• When is there a dramatic rise?
• Released by … initially, then by …

Answer 10

• Dramatic rise in the first days-weeks
• released from the corpus luteum initially, then by placenta

Question 11

Progesterone and Pregnancy

• Keeps the state of …

Answer 11

• Keeps the state of quiescence

Question 12

Oestrogen and Pregnancy

• Growth of … and enlargement of …

Answer 12

• breast growth, areolar enlargement

Question 13

HCG & Pregnancy - Clinical Picture

• Maintains corpus luteum secretion of prog & oest, … as the placental production of progesterone increases
• … unit forms the basis of pregnancy testing.
• … unit can mimic LH, FSH, and TSH
• Large quantities are released in … pregnancy and … pregnancy
• High levels cause … (hyper…)

Answer 13

• Maintains corpus luteum secretion of prog & oest, decreases as the placental production of progesterone increases
• beta unit forms the basis of pregnancy testing.
• Alpha unit can mimic LH, FSH, and TSH
• Large quantities are released in molar pregnancy and multiple pregnancy
• High levels cause vomiting (hyperemesis)

Question 14

Progesterone & Pregnancy - Clinical Picture

• Progesterone relaxes … … – everywhere!
• Maintains uterine … by … uterine electrical activity
• Constipation, … reflux, supra-… dysfunction
• … suppressor ( HLA )
• Lobulo-alveolar development in …
• Substrate for fetal adrenal corticoid synthesis eg. …

Answer 14

• Progesterone relaxes smooth muscle – everywhere!
• Maintains uterine quiescence by decreasing uterine electrical activity
• Constipation, gastric reflux, supra-pubic dysfunction
• Immune suppressor ( HLA )
• Lobulo-alveolar development in breasts
• Substrate for fetal adrenal corticoid synthesis eg cortisol

Question 15

Oestrogen & Pregnancy - Clinical Picture

• Growth of the …, … changes
• Development of … system of breasts
• Stimulation of … synthesis

Answer 15

• Growth of the uterus, cervical changes
• Development of ductal system of breasts
• Stimulation of prolactin synthesis

Question 16

The Placenta as an Endocrine Organ

• Protein hormones:
  
  • hCG (human chorionic gonadotrophin) – produced by trophoblast, first detectable 8-9 days, peaks 8-9 weeks.
  • hPL (human placental lactogen) - Similar structure to prolactin and growth hormone. Larger placenta produces … hPL. Alters maternal carbohydrate and lipid … to provide steady state of glucose for fetal requirements
  • hPG (human placental gonadotrophin) induces maternal … resistance to regulate fetal … – this may become a pathological process seen as GDM
    
    • CRH (corticotropin releasing hormone)
• Steroids:
  
  • …
  • … (oestriol)

Answer 16

• Protein hormones:
  
  • hCG (human chorionic gonadotrophin) – produced by trophoblast, first detectable 8-9 days, peaks 8-9 weeks.
  • hPL (human placental lactogen) - Similar structure to prolactin and growth hormone. Larger placenta produces more hPL. Alters maternal carbohydrate and lipid metabolism to provide steady state of glucose for fetal requirements
  • hPG (human placental gonadotrophin) induces maternal insulin resistance to regulate fetal growth – this may become a pathological process seen as GDM
    
    • CRH (corticotropin releasing hormone)
• Steroids:
  
  • Progesterone
  • Oestrogen (oestriol)

Question 17

During Pregnancy, there is a …% increase in plasma volume

Answer 17

During Pregnancy, there is a 40% increase in plasma volume - 2.5L to 3.7L (8-10kg gain)

Question 18

During Pregnancy, there is a …% increase in RBC, leading to …

Answer 18

During Pregnancy, there is a 25% increase in RBC, leading to dilutional anaemia

Question 19

During Pregnancy, Plasma colloid osmotic pressure …

Answer 19

During Pregnancy, Plasma colloid osmotic pressure falls - shift of fluid into extracellular space

Question 20

During Pregnancy, there is an … in clotting factors - … state

Answer 20

During Pregnancy, there is an increase in clotting factors - hypercoaguable state

• evolutionary balance between thrombosis and haemorrhage
• Increasine plasma fibrinogen (increased ESR), platelets, factor VIII, and von willebrand factor

Question 21

Cardiovascular System and Pregnancy

• Increased blood volume has implications on:
  
  • cardiac output (…) increase or decrease?
  • peripheral resistance (…) increase or decrease?
  • … pressure
• Heart is working hard reach supply demands of the fetus – increase in heart rate and stroke volume to account for …
  
  • Remember C.O. = … x …
  • Heart enlarges by ….% (increased venous return)
  • Innocent … murmurs are common (~90%)
  • Beware … murmur – may signify cardio…

Answer 21

• Increased blood volume has implications on:
  
  • cardiac output (increased)
  • peripheral resistance (decreased)
  • blood pressure (slightly lower)
• Heart is working hard reach supply demands of the fetus – increase in heart rate and stroke volume to account for increase in cardiac output
  
  • Remember C.O. = Stroke volume x Heart Rate
  • Heart enlarges by 12% (increased venous return)
  • Innocent systolic murmurs are common (~90%)
  • Beware diastolic murmur – may signify cardiomyopathy

Question 22

During Pregnancy, the heart is working heard to reach supply demands of the fetus. The heart enlarges by …%

Answer 22

During Pregnancy, the heart is working heard to reach supply demands of the fetus. The heart enlarges by 12%

Question 23

Innocent … murmurs are common during pregnancy

Answer 23

Innocent systolic murmurs are common during pregnancy (approx 90%)

Question 24

Beware … murmurs during pregnancy - may signify cardiomyopathy

Answer 24

Beware diastolic murmurs during pregnancy - may signify cardiomyopathy

Question 25

_Peripheral Vascular Resistance - Pregnancy_ * Peripheral vasodilatation (effect of ...) * Peripheral resistance decreases by ...% * Combined with ... cardiac output, results in slightly ... BP * Decreased vascular resistance leads to ... blood pressure

Answer 25

* Peripheral vasodilatation (effect of **progesterone**) * Peripheral resistance decreases by **35**% * Combined with **increased** cardiac output, results in slightly **lower** BP * Decreased vascular resistance leads to **lower** blood pressure

Question 26

_Pregnancy and CVS overview_

Answer 26

Question 27

_Respiratory System - Non-pregnant_

Answer 27

Question 28

_Respiratory System and Pregnancy_ * Increased ... demands * Decrease maternal p... & increase maternal p... * Increased availability of O2 to tissues and aids passive diffusion at the ..., HbF ... oxygen affinity

Answer 28

* Increased **oxygen** demands! * Decrease maternal **pCO2** & increase maternal **pO2** * Increased availability of O2 to tissues and aids passive diffusion at the **placenta**, HbF **higher** oxygen affinity

Question 29

_Respiratory System and Pregnancy_

Answer 29

Question 30

_Clinical Picture - Pregnancy & Respiratory and Cardiovascular System_ * Splinting of diaphrgm, increased ventilation – sensation of increasing ... * Raised HR leads to ... * Lots of cross over with symptoms for ... and known hypercoagulable state… leads to lots of investigations…! * Excess plasma volume shifts causing ... – peripheral * Decreased ... tolerance * Low BP causing ... / ...

Answer 30

* Splinting of diaphrgm, increased ventilation – sensation of increasing **SOB** * Raised HR leads to **palpitations** * Lots of cross over with symptoms for **PE** and known hypercoagulable state… leads to lots of investigations…! * Excess plasma volume shifts causing **oedema** – peripheral * Decreased **exercise** tolerance * Low BP causing **fainting / dizziness**

Question 31

_Musculo-skeletal / Dermatological Changes in Pregnancy_ * Increased lumbar ... * Ligamentous ... – pelvic girdle pain / pubis dysfunction * ... marks * Changes in skin ... - Linea Nigra, melasma, darkened nipples * ... Tunnel * S... * Cr..

Answer 31

* Increased lumbar **lordosis -** Lordosis is the inward curve of the lumbar spine (just above the buttocks) * Ligamentous **laxity** – pelvic girdle pain / pubis dysfunction * **Stretch** marks * Changes in skin **pigmentation** - Linea Nigra, melasma, darkened nipples * **Carpal** Tunnel * **Sciatica** * **Cramps**

Question 32

What is Sciatica?

Answer 32

Sciatica is where the sciatic nerve, which runs from your lower back to your feet, is irritated or compressed

Question 33

_Breast Changes in Pregnancy_ * oestrogen increases ... tissue – enlargement and areolar enlargements and the ductal system * Progesterone enlarges breast ...

Answer 33

* oestrogen increases **adipose** tissue – enlargement and areolar enlargements and the ductal system * Progesterone enlarges breast **lobules**

Question 34

_Urological Changes in Pregnancy_ * Kidney increases ...cm in size during normal pregnancy * increased renal flow by ...% * increased ... (BUT tubular reabsorption capacity is unchanged) - decreased glucose reabsorption - glycosuria is common * Plasma levels of creatinine and urea ... in pregnancy * ... ureters (progesterone) * Increased ... (increased urine ...)

Answer 34

* Kidney increases **1**cm in size during normal pregnancy * increased renal flow by **50**% * increased **GFR** (BUT tubular reabsorption capacity is unchanged) - decreased glucose reabsorption - glycosuria is common * Plasma levels of creatinine and urea **decrease** in pregnancy * **Dilated** ureters (progesterone) * Increased **pressure** (increased urine **frequency**)

Question 35

Kidney increases ...cm in size during normal pregnancy

Answer 35

Kidney increases **1**cm in size during normal pregnancy

Question 36

In pregnancy, increased renal flow by ...%

Answer 36

In pregnancy, increased renal flow by **50**%

Question 37

_Thyroid Changes in Pregnancy_ * ... serum T3 & T4 levels, ... in thyroid binding globulin (oestrogen) * As only unbound T3 and T4 is active, levels of free T3 and T4 .... or ... slightly

Answer 37

* **Increased** serum T3 & T4 levels, Increase in thyroid binding globulin (oestrogen) * As only unbound T3 and T4 is active, levels of free T3 and T4 **remain the same or fall slightly**

Question 38

_Physiological Changes during Pregnancy - System Overview_

Answer 38