Massive obstetric haemorrhage

[Data collection for this study is complete. Analysis in progress]


Obstetric haemorrhage, defined as bleeding from the genital tract or uterus during pregnancy or within six weeks of giving birth, was the second most common direct cause of maternal mortality between 1997 and 2005. It was the main factor leading to admission to intensive care unit (ICU) for women around the time of birth and is associated with a substantial increase in the cost of health care for women giving birth1.

It is notable that the incidence and severity of PPH is increasing in many developed countries including Australia and New Zealand (ANZ). While there are no national Australian data on major bleeding or transfusion rates in pregnancy, research data from NSW show that between 1994 and 2002 the proportion of women experiencing a PPH during the birth admission increased from 8.3% to 10.7 %, with a six fold increase of transfusion following delivery during that time2.

Transfusion support in MOH poses a significant challenge for the Blood Service and transfusion laboratories and hospitals. Massive transfusion can rapidly exhaust the hospital blood bank and Blood Service resources may require the immediate involvement of numerous clinical specialists. The Blood Service's Blood Hound project reported that while only 4% of red cells were used in obstetrics and gynaecology, 80% of these transfused units were required urgently3. Blood products are a huge cost to the community and therefore it is essential that they are used appropriately. However, there is a lack of national data on acute obstetric-related blood use. Data are needed to understand both current practice and best practice which this study can address.


This case control study will describe the current incidence, risk factors, management of MOH and the associated outcomes for these women and their infants. It will also describe transfusion requirements and clinical outcomes in relation to the transfusion. The findings from this study will contribute to evidence-based guidelines for the optimal management of massive obstetric haemorrhage.

Case definition and Inclusion criteria

All women in Australia and New Zealand who experience an obstetric haemorrhage and

  1. Bleeding originates from the uterus or the genital tract, and
  2. Haemorrhage occurs at ≥ 20 weeks gestation or within 24 hours postpartum, and
  3. Within 24 hours of haemorrhage event the woman received 5 or more units of red blood cells within 4 hours*.

* Timing of 4 hours refers to the start of the first transfusion. Fifth unit of blood needs to commence within the four hours not necessarily have been completed.


The study includes two strategies for Controls: a) the woman who gave birth immediately preceding the woman who experiences MOH (non-case); and b) geographic control(s). AMOSS sites will be randomly selected and provided with a date and time for recruitment of the geographic control(s) which will be the first women (non-case) to give birth after that specified date and time.

Surveillance period

July 2014 - June 2015

Funding and other support

We gratefully acknowledge our funding partners and participating AMOSS sites.

This study was funded by the Australian Red Cross Blood Service & Royal Hospital for Women Foundation Board.

The University of New South Wales provided support to redevelop the AMOSS site with a Major Research Equipment and Infrastructure Initiative (MREII) Grant in 2013.

Other funding support has been provided through the University of Technology Sydney.

Data collection is supported by AMOSS participating sites.


  1. Sullivan EA, Hall B and King JF. 2007. Maternal deaths in Australia 2003-2005. Maternal deaths series no 3. Cat no PER 42. Sydney: AIHW National Perinatal Epidemiology Research Unit.
  2. Cameron CA, Roberts CL, Olive EC, Ford JB, Fischer WE: Trends in postpartum haemorrhage. Aust N Z J Public Health. 2006;30(2):151-6.
  3. Shortt J, Polizzotto MN, Waters N, Borosak M, Moran M,Comande M, Devine A, Jolley DJ, Wood EM: Assessment of the urgency and deferability of transfusion to inform emergency blood planning and triage: the Bloodhound prospective audit of red blood cell use. Transfusion. 2009; 49(11):2296-303.