Effect of Pregnancy on Maternal Physiology

Question 1

Which hormone causes softening of the sacral ligaments?

Answer 1

Relaxin

Question 2

Why do pregnancy women get backache?

Answer 2

Centre of gravity changes developing an accentuated lumbar lordosis

Question 3

Why may pregnant women get varicose veins?

Answer 3

Pressure on IVC will impede venous return from the lower limbs and may impair function of valves

Question 4

What is physiological anaemia of pregnancy?

Answer 4

Haematopoiesis increases but increased plasma volume means that red cell count, haematocrit and haemoglobin are all reduced

Question 5

Why are pregnant women at risk for thromboembolism?

Answer 5

Platlets more reactive and increase in clotting factors

Question 6

What are the characteristics of uteroplacental circulation?

Answer 6

High volume, low resistance

Question 7

Why is uteroplacental low resistance?

Answer 7

Spiral arteries and arterioles lose capacity to vasoconstrict

Question 8

What happens to blood volume in pregnancy?

Answer 8

Reduced TPR triggers RAAS increasing blood volume

Question 9

What factors contribute to vasodilation in pregnancy resulting in low blood pressure?

Answer 9

Pregnancy hormones suppressing pressor (AT II) agents such as angiotensin
Oestrogen increased VEGF and NO production in endothelial cells
Endothelial cells release prostaclycin

Question 10

What happens to CO during pregnancy?

Answer 10

Increased by 30-50% during weeks 6-28

Question 11

Why may pregnant women faint when lying flat?

Answer 11

Uterus obstructs IVC decreasing venous return

Question 12

What happens to BP in pregnancy?

Answer 12

Normally falls in second trimester

Systolic falls 5-10mmHg and diastolic 10-15mmHg

Question 13

What changes occur to the respiratory system during pregnancy?

Answer 13

Progesterone increases sensitivity of central CO2 receptors
Increases tidal volume by 4%
Ventilation rate stays the same

Question 14

Why does renal function increase in pregnancy?

Answer 14

Kidneys need to deal with foetal urea

Question 15

What changes in Us & Es occur during pregnancy?

Answer 15

Urea, creatinine and uric acid decrease

Question 16

What happens to GFR during pregnancy?

Answer 16

Increases due to increased cardiac output

Question 17

Why are pregnant women prone to UTI?

Answer 17

Compression of bladder causes ureters to dilate

Question 18

How much does total body water increase by in pregnancy?

Answer 18

6-8L

Question 19

Why does blood osmolality fall in pregnancy?

Answer 19

Decreases urea and creatinine due to increased GFR

Question 20

What is morning sickness related to?

Answer 20

hCG levels

Question 21

Why do pregnant women get constipated?

Answer 21

Pressure of uterus on rectum and lower colon

Progesterone relaxes smooth muscle decreasing motility

Question 22

Why do pregnancy women get gastric reflux?

Answer 22

Pressure of uterus causes relaxation of lower oesophageal sphincter

Question 23

Why do pregnant women gain weight?

Answer 23

Breast tissue
Foetus
Placenta and amniotic fluid
Fat and extracellular fluid

Question 24

What metabolic changes occur during early pregnancy?

Answer 24

3kg fat laid down to provide energy during final trimester
Maternal tissue more sensitive to insulin
Increased protein synthesis

Question 25

What metabolic changes occur during late pregnancy?

Answer 25

Relative insulin resistance Increased lipolysis to provide energy for mother - increase in TAGs Increased requirement for protein

Question 26

What is folic acid required for?

Answer 26

Neural tube fusion

Question 27

Why should pregnant women not have too much vitamin A?

Answer 27

Can cause foetal abnormalities

Question 28

Why do calcium levels increase in pregnancy?

Answer 28

Maternal gut absorption increases (vit D3) Urinary loss decrease (PTH) Increase in calcium released from bone Active transport across placenta to calcify skeleton of foetus

Question 29

Why is zinc important in pregnancy?

Answer 29

Required for metabolic processes e.g. protein synthesis, insulin synthesis

Question 30

When should iron be given to pregnancy women?

Answer 30

If iron deficiency anaemia is present

Question 31

What hormones does the mother secrete?

Answer 31

Growth hormone Prolactin PTH Decreased FSH and LH

Question 32

What is a suggested cause of pre-eclampsia?

Answer 32

Failure of the second wave of trophoblast invasion that normally impairs the spiral arteries ability to constrict

Question 33

What are the symptoms of pre-eclampsia?

Answer 33

Hypertension Proteinuria Oedema

Question 34

Why does pre-eclampsia cause oedema and proteinuria?

Answer 34

Renal arteriolar endothelial damage from high blood pressure cause proteinuria and oedema

Question 35

When does pre-eclampsia begin?

Answer 35

20 weeks

Question 36

What is a complication of pre-eclampsia?

Answer 36

Foetal growth restriction due to reduced perfusion of placenta

Question 37

What is eclampsia?

Answer 37

Extreme hypertension which increases intracranial pressure leading to seizures, cerebral haemorrhage and coma

Question 38

What interventions are present for eclampsia?

Answer 38

Magnesium sulphate Antihypertensives Rapid delivery Careful fluid balance

Question 39

What is gestational diabetes associated with?

Answer 39

Foetal macrosomia - big baby with increased insulin resistance and high glucose