Maternal Physiology

Question 1

Explain how the CVS system changes with pregnancy

Answer 1

RAAS increases, increase in blood volume 
Increase in HR, CO and SV 
Increase in clotting factors 
BP decreases in second trimester 
IVC and aorta compression

Question 2

Explain why bp decreases during pregnancy

Answer 2

Progesterone acts upon the walls of the vasculature to decrease bp
RAAS - vasoconstriction - needs to overcome this

Question 3

What happens to the preload during pregnancy?

Answer 3

It increases due to an increase in venous pressure

Question 4

What happens to the afterload during pregnancy?

Answer 4

It decreases due to reduction in arterial pressure and therefore decreased force to expel blood

Question 5

What clotting condition is common in pregnancy?

Answer 5

Thrombus
DVT
variocoeles

Question 6

What happens to blood pressure in pre-eclampsia?

Answer 6

It increases due to increase in vasoconstriction

May be due to a defect of implantation

Question 7

What causes the changes in RAAS?

Answer 7

Oestrogen acting on angiotensin

Progesterone and oestrogen increase renin

Question 8

What happens to the respiratory system during pregnancy?

Answer 8

Increase in minute breaths but not RR
Increase in o2 uptake
Hyperventillation as foetus cannot expel CO2
Diaphragm is pushed up
Increase in TV
decrease in FRC

Question 9

What are the urinary changes during pregnancy?

Answer 9

GFR increases by 55% 
Smooth muscle effects
Increase in renin
Increase in FF
increase in filtered load
Increase in aldosterone
decrease in glucose absorption

Question 10

Explain the associated changes with the GI system and pregnancy

Answer 10

hyperinsulinisism
Smooth muscle relaxation
Nausea, vomitting, constipation, gallstones, heart burn 
Stagnation 
Viscera position is altered

Question 11

Where does the appendix move to in pregnancy?

Answer 11

RUQ

Question 12

Explain the metabolic changes with pregnancy

Answer 12

Increase in insulin during the first half to store energy for the foetus
Mother cannot utilise glucose during the second half, as it is given to the foetus and she must utilise FA
This can lead to hypoglycaemia and maternal diabetes

Question 13

What happens to PTH during pregnancy?

Answer 13

Increases due to needs of fetal skeleton of ca

Question 14

What are the risks with gestational diabetes?

Answer 14

Macrosmic fetus
Stillbirth
Increased congenital defects
Diabetes later on in life

Question 15

Explain the changes with the haematological system in pregnancy

Answer 15

Increased clotting
Increase in erythropoeitin
Increase in blood volume 
anaemia
leucocytosis

Question 16

Why are clotting factors increased in pregnancy?

Answer 16

Due to birth, the mother needs to prepare for major blood loss

Question 17

Why does anaemia occur in pregnancy?

Answer 17

increase in blood fluid volume but rbc may not be able to keep up

Question 18

What medication should be avoided during pregnancy?

Answer 18

Warfarin

Anticonvulsants

Question 19

What changes occur with the immune system in pregnancy?

Answer 19

No MHC class II on the placenta
Altered MHC class I
Altered immunity
IgG can cross the placenta 
Foetus is an allograft therefore all immune function is decreased

Question 20

Name some immune diseases that can cross the placenta

Answer 20

Graves and Hashimotos 
Haemolytic rhesus disease 
Congenital Rubella syndrome 
CMV
Toxoplasma Gondii 
herpes

Question 21

Explain the changes of the thyroid and pregnancy

Answer 21

Increase TBG

T3 and T4 increase but the free levels remain the same

Question 22

Explain the changes of the skin with pregnancy

Answer 22

Circulating melanotrophic hormone increases
Increased pigmentation on linea alba and cheeks
Hair may fall out in clumps due to follicle growth