Obstetric haemorrhage

Obstetric haemorrhage may occur before or after delivery, but more than 80% of cases occur postpartum.

Worldwide, massive obstetric haemorrhage, resulting from the failure of normal obstetrical, surgical and/or systemic haemostasis, is responsible for 25% of the estimated 358,000 maternal deaths each year.(1) In Australia, it complicates 3-6% of pregnancy.(1)

Blood loss may be:

  • Antepartum: haemorrhage after 24th week of gestation and before delivery
    • placenta praevia, placental abruption, bleeding from vaginal or cervical lesions
  • Postpartum (Primary): within 24 hours of delivery
    • Tone (uterine atony)
    • Tissue (retained products)
    • Trauma (cervical and genital tract damage during delivery)
    • Thrombin (coagulation disorder)
  • Postpartum (Secondary): 24 hours to 6 weeks post-delivery
    • uterine atony, retained products, genital tract trauma, uterine inversion

Blood loss can be notoriously difficult to assess in obstetric bleeds. Bleeding may sometimes be concealed and the presence of amniotic fluid makes accurate estimation challenging.(2)

Post-partum haemorrhage (PPH) has been defined as a blood loss of 500 mL or more during puerperium and severe PPH as a blood loss of 1000 mL or more.(3)

Goals in the management of transfusion in severe haemorrhage include:

  • rapid resuscitation with crystalloids to restore and maintain the circulating blood volume to prevent tissue and organ hypoperfusion
  • maintenance of tissue oxygenation using group specific or O negative and Kell negative red blood cells and
  • reversal or prevention of coagulopathy using appropriate blood and plasma components, ie, platelets, fresh frozen plasma (FFP), for the provision of clotting factors and cryoprecipitate or fibrinogen concentrate as a source of fibrinogen. Fibrinogen levels have to be kept higher in obstetric patients as levels below 2 g/l is an independent risk factor for development of severe PPH.(1,4) Cellular blood products should ideally be CMV negative.

Prevention and treatment of hypothermia, acidosis and hypocalemia will ensure optimal function of transfused coagulation factors.(1)

Additional guidelines on the appropriate use of blood products as well as methods to minimise blood loss are also discussed in The Royal College of Obstetrics and Gynaecologists guideline (4) and Patient Blood Management Guideline: Module 5.(5)
 

References
  1. Mclintock C, James, AH. Obstetric Hemorrhage. Journal of Thrombosis and Haemostasis, 2011;9:1441–1451
  2. Davies K, Rucklidge M. Management of Obstetric Haemorrhage. Anaesthesia UK, 2007.
  3. Royal Australian and New Zealand College of Obstetricians and Gynaecologists. Management of Postpartum Haemorrhage (C-Obs 43). Australia, 2011
  4. Royal College of Obstetricians and Gynaecologists. Blood Transfusions in Obstetrics (Green-top 47). United Kingdom, 2015.
  5. Patient Blood Management Guideline: Module 5.