Pregnancy

Question 1

Red cell mass and packed cell volume in pregnancy.

Answer 1

Increases in pregnancy. Red cell volume increases by 30% above non pregnant levels by term. This is due to raised erythropoietin.
Although anaemia of pregnancy due to proportionally larger increase in plasma volume.

Question 2

Central venouse pressure falls in pregnancy?

Answer 2

False; in the absence of IVC compression, CVP and pressure in the upper limbs is normal.

Question 3

Serum bicarbonate levels in pregnancy

Answer 3

Serum bicarbonate level decreases. This is metabolic compensation for respiratory alkalosis due to hyperventilation.

Question 4

Umbilical venous blood has pO2 of?

Answer 4

4-5kPa

Question 5

Talk about placenta and transfer of drugs

Answer 5

Barrier to drugs transfer between mother and foetus. Factors which increase transfer:
Increasing lipid solubility;
Decreasing maternal protein binding;
Decreasing MW;
Increased maternity-foetal concentration gradient (F/M ratio >1 accumulated in foetal tissues);
Placental blood flow.