Haem 11: Obstetric Haem + Haem 6 SBAs Flashcards
What happens during pregnancy from a haematological standpoint?
Volume expansion = ↑cardiac output, dilutional anaemia
Thrombocytopenia – returns to normal post-partum
Pregnancy is a hypercoagulable + hypofibrinolytic state = ↑risk of venous thromboembolism (esp in 3rd trimester)
What the haematological changes seen during pregancy biochemically?
↑↑ Plasma volume
↑ Red cell mass, MCV, WCC and Factor VII, VIII, IX, X and XII
↓ Hb, Haematocrit, Platelets, Factor XI and Protein S (most imp anticoagulant that is reduced)
Why are pregnant women at great risk of VTE?
How should they be mx?
Reduced anticoagulants \+ Increase in clotting factors \+ Uterus presses on IVC causing venous stasis in legs
Mx:
- Warfarin contraindicated
- Subcut low-molecular weight heparin preferred to IV heparin (less bleeding and thrombocytopenia)
What is HDFN?
This is haemolytic disease of feotus and newborn in prior sensitisation of Rh-negative women from previous pregnancy as these antibodies cross placenta
Key features of HDFN?
IgG-mediated
Foetal anaemia, hydrops foetalis, neonatal jaundice, kernicterus
Monitor foetus for anaemia with MCA doppler ultrasound
Mx of HDFN?
OPrevent sensitisation with anti-D Ig routinely at 28 weeks and within 72 hours of sensitising event, intra-uterine transfusion
What is HELLP syndrome?
Haemolysis, elevated liver enzymes, low platelets
Life-threatening complication associated with pregnancy - Pre-eclampsia
Key features of HELLP sydnrome? + what ddx to consider?
MAHA, ↑↑AST, ↑↑ALT, ↓platelets, normal APTT, PT
Differentials include DIC (↑APTT, ↑PT, ↓fibrinogen), AFLP (marked transaminitis)
Mx of HELLP syndrome?
Supportive + delviery of foetus
SBAs from Venous thrombosis lecture:
Which factor confers highest risk of thrombosis?
Factor V leiden Antithrombin deficiency FHx of thrombosis Reduced Factor VII 3 hour plane flight
Antithrombin deficiency
SBAs from Venous thrombosis lecture:
Which agent has delayed anticoagulant effect?
Vit K Unfractionated heparin Warfarin LMWH Aspirin
- Warfarin takes a few days to start working
- because the factors have a half-life of around 2-3 days
SBAs from Venous thrombosis lecture:
The risk of thrombosis is increased by
Reduced prothrombin Thrombocytopaenia Reduced protein C Elevated anti-thrombin Increased fibrinolysis
Reduced protein C
SBAs from Venous thrombosis lecture:
MoA of Warfarin?
Reduction of plasma procoagulant factors
SBAs from Venous thrombosis lecture:
Who is most likely to benefit from long term anticoagulation after DVT?
57y after flying from moscow 27y woman during pregnancy 33y woman on OCP 77y after hip replacement 30y after long walk
30 year old man after a long walk (because there isn’t an obvious external factor that you can attribute the DVT to
Idiopathic DVT = very high risk
SBAs from Venous thrombosis lecture:
32y woman develops DVT after removal of ovarian cyst - father and brother had DVT. What should be part of their mx?
Test for anti-thrombin deficiency
Recommend HRT
Continue long term anti coagulation
Testing for antithrombin deficiency (autosomal dominant)
SBAs from Venous thrombosis lecture:
29y man colapsed at work following PE, no FHx. What should be done?
Test for Factor V leiden
Daily aspirin
Continue long-term anticoagulation
Heparin injections for long haul flights
Continue long-term anticoagulation
NB: Factor V Leiden is autosomal dominant so would have a family history*
SBAs from Venous thrombosis lecture:
38y woman, previous DVT whilst taking COCP, 2nd DVT during pregnancy. What should be done?
Test for factor V leiden
HRT
Continue long-term anticoagulation
Fixed low-dose warfarin?
Testing for factor V Leiden
NOTE: fixed low-dose warfarin is not very good because warfarin has very variable bioavailability
SBAs from Venous thrombosis lecture:
67y man presents w/ DVT and weight loss started on LMWH
What to do?
Abdo-pelvic CT
Switch to DOAC
Switch to warfarin?
Abdo pelvic CT
If you come with idiopathic thromboembolic disease and you are > 60 years, you should be offered a CT scan to see if there is any underlying cause
A 35-year-old female who is 34 weeks pregnant presents with a swollen, painful right calf. A deep vein thrombosis is confirmed on Doppler scan. What is the preferred anticoagulant?
Subcutaneous Low Molecular Weight Heparin
Which of the following is low during pregnancy?
Fibrinogen Factor 7 Protein S Plasminogen activator inhibitor 1 Von Willebrand’s factor
Protein S - anticoagulant factor that is low in pregnancy
