Fetal Physiology

Question 1

What is the partial pressure of Oxygen in fetal blood?

Answer 1

4kPa

Question 2

Why does HbF have a greater affinity for oxygen?

Answer 2

It doesn’t bind 2,3-DPG aseffectively as HbA

Question 3

What drives hyperventilation in the mother?

Answer 3

Progesterone

Question 4

What is the purpose of ductus venosus?

Answer 4

Allows blood to bypass the liver preventing high usage of oxygen before the blood reaches the heart

Question 5

What is the purpose of the foramen ovale?

Answer 5

Shunts blood from the right artia to the left atria so that only a small amount of blood goes to the lungs. Some blood also goes into the right ventricle for development purposes

Question 6

What is the purpose of the ductus arteriosus?

Answer 6

Shunts blood from the right ventricle and pulmonary trunk to aorta, prevents lots of blood being sent to the lungs

Question 7

How much amniotic fluid is there at 38 wks?

Answer 7

1 litre

Question 8

How much fetal urine is produced per day in T2/3?

Answer 8

800ml

Question 9

What is the contents of amniotic fluid?

Answer 9

Water, electrolytes, creatinine, urea, bile pigments, glucose, hormones etc-

Question 10

Why is physiological jaundice common?

Answer 10

Liver and Intestinal process for metabolism conjugation and excretion is immature at birth. More common in premature babies