Haematological Disorders Flashcards
How is anaemia defined in pregnancy?
1st trimester <110 g/l
2nd/3rd trimester <105 g/l
Postpartum <100 g/l
At what point are pregnant women screened for anaemia?
28w gestation
How should anaemia in pregnancy be managed?
Oral iron 100-200mg
Folate supplementation 5mg daily
Beta thalassaemia: folate supplementation and blood transfusions
Sickle cells: folate +/- iron supplementation
Define antiphospholipid syndrome
Autoimmune, Ab are targeted against phospholipid-binding proteins (major component of cell membranes).
Characterised by vascular thrombosis and/or adverse pregnancy outcomes.
APS is a major treatable cause of recurrent miscarriage, with antiphospholipid antibodies present in 15% of women with recurrent miscarriage
What are the obstetric complications of antiphospholipid syndrome
Inhibition of trophoblastic (precursor to the placenta) function and differentiation.
Activation of complement pathways at the maternal–fetal interface.
Thrombosis of the uteroplacental vasculature (late pregnancy).
What are the clinical features of antiphospholipid syndrome
Thrombosis formation: ischaemic stroke, DVT, PE, MI, retinal thrombosis
Recurrent preg loss
Livedo reticularis: red/blue/purple reticular pattern on skin of the trunk, arms or legs
Valvular heart disease: particularly aortic and mitral regurgitation
Renal impairment: ischaemia in the small vessels of the kidney can result in CKD
Thrombocytopaenia
How is antiphospholipid syndrome diagnosed?
Anticardiolipin = detects Ab that bind cardiolipin (a phospholipid).
Lupus anticoagulant = measures the clotting ability of the blood. In vitro, blood containing antiphospholipid Ab has a prolonged clotting time
Anti-B2-glycoprotein I = detects Ab that binds B2-glycoprotein I (a molecule that binds with cardiolipin).
Outline how antiphospholipid syndrome should be managed?
Recurrent preg loss = LMWH, low dose aspirin throughout subsequent preg
Previous pre-eclampsia or intrauterine growth restriction = low dose aspirin throughout subsequent preg
Vascular thrombosis = long term warfarin, switch to LMWH in preg
Why does preg increase the risk of VTE?
Increased levels of proteins in the clotting cascade = fibrinogen
Decreased protein S
How should VTE be investigated?
Rise in D-dimer during preg is normal (so do not test)
DVT = compression duplex USS
PE = ECG, ABG, CTPA, V/Q scan
Outline the management of VTE during preg
LMWH until 6-12 weeks post-partum
Women should be advised to omit their dose 24 hours before any planned induction of labour or caesarean section. Furthermore, they should not take their dose if they think they are going into labour.
No warfarin = teratogenic
When is anti-D given during pregnancy and how does it work?
Given = 28w + 34w, and any time there is possible blood exposure
Neutralises any RhD positive antigens
