Haematology in Pregnancy Flashcards
What are the immunological changes in pregnancy?
- rise in neutrophils and monocytes
- no changes in immunoglobulins and lymphocyte subsets
- BUT some infections are more common or severe in pregnancy
What is immune tolerance and how does the body establish this during pregnancy?
- immune tolerance is how the body responds to the foetus and placenta during pregnancy
- counters the body’s usual natural response (rejection) to the presence of foreign material
- as the trophoblast invades the decidua there is an increase in uterine NK and dendritic cells allowing the remodelling of the uterine wall rather than cytotoxic or antigen presenting function
- infrequent lymphatic changes and minimal lymphoid tissue
What are the physiological changes in pregnancy?
- Hb declines to 110-100g/l (anaemia common)
- increase in red cells, bigger increase in plasma volume
- rise in WBC (mainly neutrophils)
- fall in platelets (gestational thrombocytopenia)
- rise in mean cell volume
- rise in fibrinogen and factors VIII, IX and X (coagulation factors)
Describe immune thrombocytopenic purpura (ITP)
- autoimmune disease
- triggered by infection/drug/pregnancy
- formation of autoantibodies against platelets
- if pregnant risk of neonatal thrombocytopenia due to IgG antibodies crossing placenta
What is the treatment for ITP?
- watch and wait
- steroids
- immunoglobulins
- splenectomy
- drugs to mimic thrombopoietin
Describe thrombotic thrombocytopenic purpura (TTP)
- life-threatening thrombotic microangiopathy
- can be associated with autoimmune disease/HIV/pregnancy
- enzyme that prevents large Von Willebrands polymers (ADAMS13) becomes deficient and causes platelets to aggregate
What is the clinical presentation and treatment of TTP?
Presentation:
- fever
- neurological disease
- renal disease
- low platelets
- fragmented red cells
- normal coagulation screen
- treated with plasma exchange to replace the enzyme
What factors put you at risk of thromboembolic disease?
- pregnant
- 6 weeks post partum
- age
- previous clot
- smoking
- twins
- obesity
- thombophilia
What are some signs of thromboembolic disease in pregnant women?
- leg swelling (due to compression of pelvic veins)
- causes progressive pain, tenderness
- unilateral swelling
What imaging can you use to look for thromboembolic disease in pregnant women?
- doppler exam on swollen leg
- chest X-ray
- if abnormal then do a CT pulmonary angiogram
What is the treatment and future management of thromboembolic disease in pregnant women?
- LMW heparin
- due to increased rate of clearance and volume of distribution will need twice the daily dose
- need to monitor anti Xa levels 3-4 hrs after dose to see if it is effective
- for future pregnancies will need prophylactic anticoagulation
What are the signs of pre-eclampsia, its major complication and treatment?
Signs of pre-eclampsia:
- hypertension
- fluid retention
- proteinuria
- headache
- high urate
- major complication is HELLP syndrome (haemolytic anaemia, red cell fragmentation, raised LDH, liver enzymes, low platelets)
- treatment: prompt delivery of baby and supportive care
What is disseminated intravascular coagulation, how it manifests and its treatment?
it is an acute and serious complication from:
- placental abruption
- amniotic fluid embolism
- dead foetus
- haemorrhagic, organ failure, depletion of coagulation factors, low platelets and red cell fragments
- treatment: treat cause, coagulation factors and platelets
What are the risk factors for haemorrhage?
- placenta praevia (placenta sits lower, over cervix)
- placental abruption
- retained products of conception
- poor uterine contraction after delivery
Describe the WIlson and Jungner screening criteria
- there should be a recognisable latent or early symptomatic stage
- it should be a simple test with high sensitivity and specificity
- the test should be acceptable to the population
- early effective treatment needs to be of clear benefit
- there should be an agreement as to who should be treated
- condition is important health problem
- diagnosis and treatment should be cost effective
- case finding should be continuous process
- natural history understood
- should be cost effective overall
