Session 8- Maternal Physiology and Pregnancy

Question 1

what 4 hormones drive the adaptations in pregnancy

Answer 1

hCG
oestrogen
Progesterone
relaxin

Question 2

how does the mum immune system adapt

Answer 2

To prevent rejection of the fetus, there is a reduction in cell-mediated immunity and TH1 cytokine production.

This is balanced by an increase in TH2 cytokines and humoral immunity. This means that pregnancy can improve TH1 mediated conditions, like psoriasis, and worsen TH2 mediated conditions like eczema.

hCG also suppresses IgA, IgG and IgM production, leading to maternal immunosuppression.

Question 3

what are the consequences of the shift in immune system of the mother

Answer 3

-mother is in an immunosuppressed state so is more susceptible to infection (flu)

Question 4

why does respiration need to change in pregnancy

Answer 4

baby needs

• o2 delivery
• co2 removal

mum needs

• o2 delivery to organs and periphery
• increased o2 supply and co2 clearance

Question 5

how does resp change in pregnancy

Answer 5

overall increase in tidal volume by 30-40% which increases minute ventilation by 50%

pH change

Question 6

how is the change in resp achieved

Answer 6

the ERV is increased which increase TV

Question 7

how does TLC change and why

Answer 7

decrease by 5%

elevation of diaphragm

Question 8

what causes dyspnoea in pregnancy

Answer 8

hyperventilation and decreased PaCo2

Question 9

what is hyperventilation

Answer 9

minute vent goes up no RR

Question 10

adaptations in CVS- volume

Answer 10

in early pregancy increased stroke volume and cardiac output
in late pregnancy increased HR

increased progesterone

Question 11

how does progestrone affect the CVS in pregnancy and what is the effect of this

Answer 11

smooth muscle relaxation

• decreased Systemic vascular resistance
• drop in BP (Tri 1& 2)

Question 12

what is the normal BP in pregnancy

Answer 12

140/90

Question 13

how is clotting affected in pregnancy

Answer 13

increased procoaglulants
decreased antocoagulants
reduced fibrinolysis

hypercoagulable state- increased no of thromboembolic events

Question 14

consequences of changes in CVS

Answer 14

hypercoagulable state- increased thromboembolic state

change in plasma volume» change in RBC volume (dilutional anaemia)

increased RAAS- increased BP

Question 15

how does renal/urinary system adapt- physiology

Answer 15

systemic vasdilation = increased RBF

• increased GFR by 50%
• decrease serum urea and creatinine ny 25%

decreased PCT absorption
-Glucosuria ( cant keep up with high GFR)

Question 16

how does the renal system adapt structurally

Answer 16

structural

• smooth muscle relaxation and obstruction
• increased lidney size and ureters
• decreased speed of urine passage

Question 17

how does the GI system adapt

Answer 17

progesterone causes smooth muscles relaxation throughout the GI tract which causes slow gastric emptying and can cause common symtoms of nausea, constipation and heartburn.

gallbladder emptying is reduced

Question 18

adaptations of the thyroid

Answer 18

• oestrogen stimulates TBG hepatic production

- hCG has a similar alpha subunit to TSH so has a weal stimulating effect on thyroid

Question 19

how does calcium metabolism change

Answer 19

the placenta contributes to the synthesis of calcitrol which aims to increase calcium absorption - more availibility for the foetus

Question 20

what are the changes to glucose metabolism

Answer 20

glucose and amino acid metabolism are altered in pregnancy to favour nutritional supply to the fetus

• reduction in maternal blood glucose and amino acid concentrations
• diminished maternal responsivenes to insulin in second half of pregancy
• increase in maternal free fatty acid, ketone and triglyceride levels
• increased insulin release

Question 21

what generates a maternal resistance to insulin

Answer 21

HPL human placental lactogen

Question 22

what role does oestrogen play in adapting glucose metabolism in pregnancy

Answer 22

stimulates an increase in prolactin

Question 23

what role does progestrone play in adapting glucose metabolism in pregnancy

Answer 23

increases appetite in the first half of preganacy and diverts glucose into fat synthesos

Question 24

what is gestational diabetes

Answer 24

glucose intolerance that is first recognised in pregnancy and doesnt persist after delivery

where the resistance to insulin isnt met with a compensatory rise in maternal insulin leading to maternal hyperglycaemia

Question 25

how is gestational diabtetes diagnosed

Answer 25

oral glucose tolerance test

Question 26

what causes teh back and shoulder pain, tension and headaches

Answer 26

adaptations to MSK-
change in centre of gravity
-increased lordosis and kyphosis
-forward flexion of neck

stretching of adominal muscles

• impede postire
• strain paraspinal muscles

Question 27

what causes the pelvic pain

Answer 27

adaptations to MSK
-increased mobility of sacroiliac joints and pubic symphysis
anterior tilt of pelvis

Question 28

which nerve commonly gets compressed and why

Answer 28

median- fluid retention can compesses it

Question 29

adaptations in skin

Answer 29

melasma
palmar erythema
vascular spiders
linea nigra

Question 30

what is pre-eclampsia

Answer 30

hypertension and proteinuria

impaired invasion of trophoblast leading yo shallow invasian of spiral arteries leads to hypoperfusion and ischemia- systemic endothelial dysfunction