Physiology of pregnancy

Question 1

How does blood volume change during pregnancy?

Answer 1

• begins increasing during first trimester
• expands rapidly in second
• increases at lower rate during third

Question 2

How much does plasma volume change during pregnancy?

Answer 2

45%

Question 3

Why does haemoglobin concentration decrease during pregnancy?

Answer 3

Increase in RBC number is slight

Significant increase in plasma volume, so diluted

Question 4

How much does peripheral vascular resistance decrease by in early pregnancy?

Answer 4

50%

Question 5

How much does red cell mass increase by during pregnancy?

Answer 5

20%

Question 6

How does cardiac output increase during pregnancy?

Answer 6

35-40% during first trimester

50% at term

Question 7

Which organ experiences the highest increase in CO during pregnancy?

Answer 7

Uterus

Question 8

When does blood pressure reach its lowest point?

Answer 8

17-24 weeks

Question 9

Which in biggest factor causing drop in blood pressure in pregnancy?

Answer 9

Decrease in peripheral vascular resistance

Question 10

What mediates the decrease in peripheral vascular resistance?

Answer 10

hormones of pregnancy (oestrogen and progesterone)

NO, relaxin and calcitonin gene-related peptide

Question 11

What characterises pre-eclampsia?

Answer 11

Rising arterial blood pressure
Oedema
Proteininuria

Question 12

Why shouldn’t pregnant women lie supine

Answer 12

Enlarged uterus compresses IVC

Resulting in reduction of CO and BP

Question 13

What factors does process of coagulation depend upon?

Answer 13

Balance of clotting formation and clot dissolving

Question 14

What is the main haemostatic change that occurs during pregnancy

Answer 14

Pregnancy proposed towards hypercoagulable state

Question 15

Purpose of haemostatic changes?

Answer 15

• Maintain placental function

- Prevent excessive blood loss

Question 16

How does platelet production and platelet count change

Answer 16

Platelet production increases

Platelet count decreases

Question 17

How does oxygen consumption change during pregnancy?

Answer 17

increases from 250ml/min to 300ml/min at rest

Question 18

What respiratory changes occur during pregnancy?

Answer 18

Increased alveolar ventilation

Increased minute ventilation

Question 19

How is respiratory centre stimulated during pregnancy?

Answer 19

Progesterone mediated hypersensitity of CO2

Question 20

How does lung volume

and lung capacity change during pregnancy?

Answer 20

Voume-Increases

Capacity- decreases

Question 21

What structural changes occur in the kidney

Answer 21

Increases in length

Question 22

What is the impact of progesterone on the kidney

Answer 22

Dilation of renal calcycles, pelvis and ureter

Question 23

What changes in renal function occur in pregnancy?

Answer 23

Increase in clearance of urea, creatinine and ureate, increase in excretion of bicarb

Question 24

How does RAAS change during pregnancy?

Answer 24

Increased RAAS activity leads to water retention

High levels of angiotensin II

Question 25

Why is high levels on angiotensin II important?

Answer 25

Maintain blood volume, blood pressure and uteroplacental blood flow

Question 26

Effect of oestrogen on RAAS system

Answer 26

acts directly to increase renin secretion from granular cells acts to upregulate

Question 27

Why is heart burn and reflux more common in pregnancy?

Answer 27

Increased intra-abdominal pressure

Question 28

How does pancreatic function change during pregnancy?

Answer 28

More insulin production becuse pancreatic islets of Langerhans experience hyperplasia

Question 29

What is glycosuria

Answer 29

Decrease in glucose reabsorption

Question 30

How does cardiac output change post partrum?

Answer 30

Blood volume decreases by 20% 72 hr post partum | HR and CO return to baseline in 2 weeks

Question 31

How and when do functional changes occur to bladder post partum

Answer 31

How- prompt return to baseline w decrease blood volume | When- prompt

Question 32

How and when do structural changes occur to bladder post partum

Answer 32

Dilation of bladder, uterus and renal pelvis occur 3 months or mroe

Question 33

When does development of mammary glands begin

Answer 33

Puberty

Question 34

How does breast adapt during pregnancy

Answer 34

- Lobular ductal alveolar sytem undergoes hypertrophy | - Proliferation of ducts, alveoli mature, deposition of adipose tissue between lobules of glands

Question 35

What controls breast adaptation during pregnancy

Answer 35

Placental steroids | Estradiol and prosterone and well as placental peptide hormone

Question 36

What is the primary lactation hormone?

Answer 36

Prolactin

Question 37

What inhibits secretory activity

Answer 37

Steroid secretion

Question 38

How is milk triggered post delivery

Answer 38

Fall in steroid secretions

Question 39

What hormone controls the milk ejection reflex

Answer 39

Oxytocin