GTG47 May 2015
Obstetric haemorrhage remains a major cause of maternal mortality in the UK and is now the third leading cause
of direct maternal deaths, accounting for approximately 10% of direct deaths
Reducing Risk of Transfusion
- Anaemia in pregnancy is defined as
- first trimester haemoglobin (Hb) less than 110 g/l,
- second/third trimester Hb less than 105 g/l,
- and postpartum Hb less than 100 g/l, in line with BCSH guidance
For normocytic or microcytic anaemia, a trial of oral iron should be considered as the first step and further
tests should be undertaken if there is no demonstrable rise in Hb at 2 weeks and compliance has been
checked
• - Should be offered FBC screening for anaemia at booking and at 28 weeks.
- Women with multiple pregnancies should have an additional FBC done at 20–24 weeks
- Serum ferritin is the most useful test for diagnosing iron deficiency
- Oral iron should be the preferred first-line treatment for iron deficiency
Antenatal use of iron, with or without folic acid, showed a 50% reduction in the risk of anaemia in the third
trimester or at delivery
•
Parenteral iron is indicated when oral iron is not tolerated or absorbed or patient compliance is in doubt or if
the woman is approaching term and there is insufficient time for oral supplementation to be effective
• - Recombinant human erythropoietin (rHuEPO) for non-end-stage renal anaemia is still to be established
- Active management of the third stage of labour
- Principles of Blood Transfusion
- Valid consent
Blood Transfusion In an emergency, where it is not feasible to get consent, information on blood transfusion should be provided retrospectively
Requirements for group and screen samples and crossmatching
All women should have their blood group and antibody status checked at booking and at 28 weeks of gestation - Group and screen samples used for provision of blood in pregnancy should be less than 3 days old
In a woman at high risk of emergency transfusion – , e.g. placenta praevia, and with no clinically significant
alloantibodies, group and screen samples should be sent once a week to exclude or identify any new antibody
formation and to keep blood available if necessary
•
Blood product specification in pregnancy and the
puerperium - ABO-, RhD- and K- (Kell-) compatible red cell units should be transfused
Cytomegalovirus- (CMV-) seronegative red cell and platelet components should be provided for elective
transfusions during pregnancy
• - The UK policy of universal leucocyte depletion substantially reduces the risk of CMV transmission
In an emergency, such as major haemorrhage, standard leucocyte-depleted components should be given to
avoid delay and CMV-negative blood or platelets are not needed for transfusion during delivery or in the
postpartum period
•
Predelivery autologous blood deposit – is not recommended
Intraoperative cell salvage (IOCS)
Cell salvage is recommended for patients where the anticipated blood loss is great enough to induce anaemia
or expected to exceed 20% of estimated blood volume.
•
Where IOCS is used during caesarean section in RhD-negative, previously nonsensitised women and where
cord blood group is confirmed as RhD positive (or unknown), a minimum dose of 1500 iu anti-D immunoglobulin
should be administered following the reinfusion of salvaged red cells
•
A maternal blood sample should be taken for estimation of fetomaternal haemorrhage 30–40 minutes after
reinfusion in case more anti-D is indicated
•
The NICE guideline on IOCS in obstetrics states that this procedure should only be performed by
multidisciplinary teams who have regular experience of IOCS
•
What blood components can be used for obstetric
Anaemia Page 228
What blood components can be used for obstetric
haemorrhage
There are no firm criteria for initiating red cell transfusion. The decision to provide blood transfusion
should be made on clinical and haematological grounds
• - When the blood group is unknown, group O RhD-negative red cells should be given
Blood transfusion is almost always required when the Hb is less than 60 g/l and it is rarely required when
the Hb is greater than 100 g/l
•
It should also be remembered that patients with acute haemorrhage can have normal Hb; hence the clinical
evaluation of the patient in this situation is extremely important
•
In what circumstances should fresh frozen plasma (FFP)
and cryoprecipitate be used
It is essential that regular full blood counts and coagulation screens (PT, APTT and fibrinogen) are
performed during the bleeding episode
•
FFP at a dose of 12–15 ml/kg should be administered for every 6 units of red cells during major obstetric
haemorrhage.
•
Subsequent FFP transfusion should be guided by the results of clotting tests if they are available in a timely
manner, aiming to maintain prothrombin time (PT) and activated partial thromboplastin time (APTT) ratios at
less than 1.5 x normal
•
Once the FFP has been ordered, it takes at least 30 minutes to thaw and issue.52 During this time,
resuscitation should be continued with volume expanding fluids or red cells as appropriate
•
FFP (as is the case with red cells, platelets and cryoprecipitate) are not virally inactivated and that
transfusion with these products offers a small risk of transfusion-transmitted infection
•
Cryoprecipitate at a standard dose of two 5-unit pools should be administered early in major obstetric
haemorrhage. Subsequent cryoprecipitate transfusion should be guided by fibrinogen results, aiming to keep
levels above 1.5 g/l (PPH Guideline says >2g/l)
•
The FFP and cryoprecipitate should ideally be of the same group as the recipient. If unavailable, FFP of a
different ABO group is acceptable providing that it does not have a high titre of anti-A or anti-B activity
• - No anti-D prophylaxis is required if a RhD-negative woman receives RhD-positive FFP or cryoprecipitate
When should platelets be used - A platelet transfusion trigger of 75 x 109 /l is recommended to provide a margin of safety
- Aim to maintain the platelet count above 50 x 109 /l in the acutely bleeding patient
The platelets should ideally be group compatible. RhD-negative women should also receive RhD-negative
platelets
•
If RhD-positive platelets are transfused to a RhD-negative woman of childbearing potential, anti-D
immunoglobulin should be administered. A dose of 250 iu anti-D immunoglobulin is sufficient to cover five
adult therapeutic doses of platelets given within a 6-week period. This may be given subcutaneously to
minimise bruising and haematomas in thrombocytopenic women
•
Anaemia Page 229
minimise bruising and haematomas in thrombocytopenic women
Is there a role for near patient testing of coagulation
Rotation thromboelastometry (ROTEM®, Tem, Munich, Germany) for guiding blood transfusion during major
obstetric haemorrhage must ensure that their transfusion algorithm protocol has been validated
Is there a role for recombinant factor VIIa (rFVIIa)
therapy
The use of rFVIIa may be considered as a treatment for life-threatening PPH, but should not delay or be
considered a substitute for a live-saving procedure such as embolisation or surgery, or transfer to a referral
centre
Is there a role for fibrinogen concentrate therapy
Fibrinogen concentrate is not licensed in the UK for the management of acquired bleeding disorders
Is there a role for antifibrinolytic
Tranexamic acid is a synthetic derivative of the amino acid lysine that reversibly binds to the lysine-binding sites
of the plasminogen molecule. In doing so, it prevents activation of plasminogen to plasmin, leading to inhibition of
fibrinolysis. The CRASH-2 study showed that tranexamic acid reduces mortality in bleeding trauma patients
without an increase in the rate of venous thromboembolism – MRCOG MCQ
How should intrapartum anaemia be managed
If the Hb is less than 70 g/l in labour or in the immediate postpartum period, the decision to transfuse
should be made according to the individual’s medical history and symptoms
•
If the Hb is less than 70 g/l in the postnatal period, where there is no ongoing or threat of bleeding, decide
on transfusion
•
How should women who decline blood products be managed? - Hb should be optimised prior to delivery to prevent avoidable anaemia
Anaemia
Consent/refusal of blood and components or other transfusion-sparing techniques should be discussed and documented during the antenatal period
•
Use of pharmacological, mechanical and surgical procedures to avert the use of banked blood and blood
components should be considered early
• - IOCS has a role in the management of patients who refuse allogeneic blood transfusion
Jehovas Witness – MRCOG MCQ
Nearly all Jehovah’s Witnesses refuse transfusions of whole blood (including preoperative autologous donation)
and the primary blood components – red cells, platelets, white cells and unfractionated plasma. Many Witnesses
accept the transfusion of derivatives of primary blood components such as albumin solutions, cryoprecipitate,
clotting factor concentrates (including fibrinogen concentrate) and immunoglobulins. There is usually no objection
to intraoperative cell salvage (ICS), apheresis, haemodialysis, cardiac bypass or normovolaemic haemodilution
providing the equipment is primed with non blood fluids. Recombinant products, such as erythropoiesis
stimulating agents (e.g. RHuEpo) and granulocyte colony stimulating factors (e.g. G-CSF or GM-CSF) are
acceptable, as are pharmacological agents such as intravenous iron or tranexamic acid
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