Flashcards in Haemoglobinopathies and Obstetric Haematology Deck (22)
What are the main haematological changes during pregnancy?
Plasma vol. expands by 50%
Red cell mass expands by 25%= haemodilution and decreased in relative MCH +/-anaemia
Increased requirement for Fe and folic acid
Leucocytosis- immature WBCs sometimes seen in peripheral blood
Hypercoaguable stage (liver increased production of clotting factors)
Overall, is pregnancy a hyper or hypo coagulable state?
Hypercoaguable- settles down 6-8 weeks after birth
Detection of what foetal haemaglobinopathy would prompt genetic counselling and the decision to terminate the foetus
Thalassamia major (B)
How is thalassaemia inherited?
What are the most common single gene disorder
Why does alpha thalassamia have a worse prognosis than beta thalassaemia?
Alpha globin is present in adult and foetal haemoglobin
What are the lab findings for alpha and beta thalassaemia trait?
Microcytic, hypochromic RBCs with raised red cell count
Lifespan of sickle cells
What type of anaemia do you get in sickle cell disease?
What type of mutation causes sickle cell disease?
Point mutation in the beta globin gene-
What is the result of the mutation in sickle cell disease?
Insolubility of HbS in deoxygenated state
4 clinical features of sickle cell disease
Visceral suquestrian crisis
Increased susceptibility to infection
Increased sickling and blockage of small vessels. Triggers include infection, dehydration, acidosis and deoxygenation. Hand- foot syndrome in children- infarction of metaphyses of small bones- pain and blistering
Sickling with pools of RBCs in liver and spleen or lungs. Partly responsible for acute chest pain
Visceral sequestrian crisis
Follos B19 paravirus. Arrest of erythropoieisis is normal, but in HbS patients, rapidly causes severe anaemia.
Treatment for sickle cell disease
Transfusion for severe anaemia
Oral hydroxycarbamide, increases Hbf and inhibits prothrombotic state, increases MCV
Stem cell transplant
Clincial features of thalassaemia major
Anaemia at 3-6 months when foetal to adult Hb chain occurs. Failure to thrive, infection, pallor, mild jaundice, bone marrow hyperplasia esp skull 'hair on end' appearance on x ray. osteoporosis= bone marrow expansion
Lab findings for thalassaemia major
Hypochromic, microcytic cells
Life expectancy for thalassaemia major
Treatment for thalassaemia major
Transfusion to suppress natural erythropoiesis.
Complications of treatment for thalassaemia major
No excretory mechanism for Fe, by 10-12 years- severe iron overload and toxicity.