Flashcards in Haematology 9 - Obstetric haematology Deck (25)
What change in Hb concentration occurs in pregnancy and why?
Lower concentration (mild anaemia)
Red cell mass rises 125%
Plasma volume rises 150%
So [Hb] falls
What is the most common cause of anaemia in pregnancy?
Physiological rather than a deficiency
What change occurs in the neutrophil count in pregnancy?
Physiological fall, particularly towards the end
How do platelets change in pregnancy?
Increase in size (but decrease in number)
What is the foetal requirement of iron in pregnancy?
What is the RDA of iron in pregnancy?
What is the iron requirement for red cell expansion in pregnancy?
When is the folic acid supplement recommended in pregnancy?
400 ug: Before conception and for >12 weeks gestation
What are the cutoffs for normal haemoglobin expected in each trimester of pregnancy?
What are the most important differentials in microcytic anaemia in pregnancy to consider?
What might cause thrombocytopaenia in pregnancy?
1. Mostly gestational (physiological) thrombocytopaenia
2. Pre-eclampsia (often causes DIC)
3. Immune thrompocytopaenia (ITP) - this can be unmasked by pregnancy (but would be present already)
What platelet count is necessary for a woman to have spinal anaesthesia when giving birth?
Give 2 options for ITP treatment in pregnancy
Steroids/azothioprine to immunosuppress
In which type of thrombocytopaenia in pregnancy can the baby be affected?
What is the key feature of MAHA?
Deposition of platelet-rich clots in blood vessels (rather than fibrin-rich)
What will be seen on a blood film of someone with MAHA?
Shistocytes (red cell fragments)
Where is venous thromboembolism most common in pregnancy?
When is risk of venous thromboembolism most likely in pregnancy?
6 weeks after pregnancy
Is venous thromboembolism more likely in vaginal birth or C section?
What is the leading cause of mortality in pregnancy?
Summarise the coagluation factor changes in pregnancy
Factor VIII and vWF increases 3-5 fold
Fibrinogen, factor VII and factor X also increase
--> hypercoagulable state
Protein S falls to half basal
Why does pregnancy cause a hypofibrinolytic state?
Increase in PAI-2
PAI inhibits Urokinase and Tissue Plasminogen Activator which both promote fibrolysis
Therefore more PAI --> less fibrinolysis
Why do you not do a D-dimer in pregnancy when there is suspected VTE?
Because it will be raised anyway
Which anti-coagulant should never be used in pregnancy?
Warfarin (cross the placenta)