Haematology: Haemoglobin Production Flashcards
Where is the main site of haematopoiesis in fetal life?
The liver
Where is the main site of haemopoiesis throughout postnatal life?
The bone marrow
What is the main Hb throughout fatal life?
Fetal haemoglobin (HbF)
What subunits is fetal haemoglobin comprised of?
2 alpha and 2 gamma
Does fetal or adult haemoglobin have a higher affinity for oxygen?
Fetal - better at holding onto oxygen, which is an advantage in the relatively hypoxic environment of the fetus
What are the adult haemoglobin subunits?
HbA = 2 alpha and 2 beta
At birth what are the types of Hb present?
HbF, HbA, HbA2
When is HbF replaced by HbA and HbA2?
Gradually replaced during first year of life
By 1 year of age, is the percentage of HbF high or low?
Low in a healthy child
Why do the signs of sickle cell disease only present later in the first year of life and not as a newborn?
The higher HbF in the first few months is protective in some types of inherited anaemia
At birth, is the Hb in term infants high or low?
High 140-215g/L to compensate for the low oxygen concentration in the fetus
After birth, when does the Hb fall?
Over the first few weeks due to the reduced red cell production
At 2 months Hb = 100g/L
Do preterm infants have a steeper or slower fall in Hb after birth?
Steeper fall to a mean of 65-90g/L at 4-8 weeks
Are stores of iron, B12 and folic acid in term and preterm babies adequate at birth?
Yes, but in preterm stores of iron and folic acid are lower and deplete quicker - deficiency after 2-4 months if recommended daily intake not maintained
Are WBCs higher or lower in neonates than older children ?
Higher
