Maternal physiological adaptations to pregnancy

Question 1

How much weight does a women gain in pregnancy

Answer 1

0.3-0.5 kg a week

Total of 12.5 kg

Question 2

What causes a lower pH in pregnancy

Answer 2

Increase in bacteria

Question 3

By what factor does the blood supply in the uterus increase?

Answer 3

10X

Question 4

Give three changes to cervix in pregnancy

Answer 4

1. increase in number of glands and secretion in the cervix
2. Fills with thick mucus plug
3. Cervix and vagina become more elastic to permit dilatation

Question 5

What influences duct proliferation in pregnancy

Answer 5

Oestrogen, growth hormones and glucocorticoids

Question 6

What stimulates alveolar/lobules to proliferate

Answer 6

Progesterone and prolactin

Question 7

State 5 haematological adaptations

Answer 7

Increase in blood volume (30%)
Increase in plasma volume
Increase in red blood cells
Decrease in albumin
Increase in clotting factors/fibrogen

Question 8

State 3 consequences of the haematological adaptations

Answer 8

Haemodilution (because increase in plasma volume greater than increase in blood volume)
Oedema
Deep vein thrombosis (due to increased clotting factors)

Question 9

Describe the 2 stages of oedema developing normally

Answer 9

1. -vely charged proteins in the blood attract H+ so H20 moves into circulation
2. If decreased proteins in circulation more H2) stays in the interstitium

Question 10

Why does oedema occur in pregnancy?

Answer 10

Because the decrease in albumin in blood causes more water to stay in the interstitial space as oncotic pressure lower

Question 11

Why does mother reject the fetus?

Answer 11

Because maternal lymphocyte count is maintained but function and cell mediated immunity decrease (makes mother susceptible to infection)

Question 12

State 4 maternal cardiac adaptations

Answer 12

1. Hypertrophy
2. Increase in CO
3. Peripheral resistance is decreased via vasodilation
4. Progesterone relaxes smooth muscle and influences HR

Question 13

Describe the changes in the mothers blood pressure

Answer 13

1. Initially a decrease in bp
2. Increased blood flow (particularly to uterus)
3. Return to normal bp at third trimester

Question 14

What is increase in bp a sign of?

Answer 14

Pre-eclampsia

Question 15

How do the cardiac adaptations manifest clinically?

Answer 15

Displaced apex beat

Ejection systolic flow murmur

Question 16

Why does cardiac output decrease by 30% in pregnancy when supine

Answer 16

Uterus compresses IVC (so HR increases)

Question 17

Which hormone increases the sensitivity of the Central respiratory centre to CO2 and stimulates respiration (increase in tidal volume not rate)in pregnancy

Answer 17

Progesterone

Question 18

How does pregnancy affect the functional residual capacity of the mother?

Answer 18

Increases intra-abdominal pressure due to fetus

Diaphragm rises by 4cm and thoracic cage circumference increases by 5cm so FRC is REDUCED

Question 19

Clinical importance of respiratory changes in pregnancy

Answer 19

Respiratory rate doesn’t increase so if it does could indicate sepsis
O2 sats decrease gradually

Question 20

Give 8 renal adaptations in pregnancy

Answer 20

1. Increase renal blood flow
2. Increase GFR
3. Increase urinary output
4. Increase water retention
5. Mild proteinuria and glycosuria
6. Increase in size of kidneys and ureters
7. Relaxation of ureter smooth muscle
8. urinary stasis which increases risk of UTI and polynephritis

Question 21

Why is there more insulin resistance in pregnancy?

Answer 21

Increase in glucose in the blood