Studies

Antenatal pulmonary embolism

Background

Thrombosis and pulmonary embolism is a prominent cause of maternal death in Australia. 1There are no available, reliable data on the incidence and management of non-fatal pulmonary embolism during pregnancy in Australia. The UKOSS reported an incidence of antenatal pulmonary embolism of 1.3 per 10 000 maternities and importantly found that the national guidelines for the prevention of thrombosis during pregnancy were not optimally implemented.2 There is a need in Australia to improve understanding of antenatal pulmonary embolism. The incidence of antenatal pulmonary embolism, the risk factors and management of the condition warrant investigation.

Research questions

  1. What is the current incidence of antenatal pulmonary embolism (APE) in Australia?
  2. How is antenatal pulmonary embolism managed in Australia?
  3. What are the outcomes for both mother and infant of antenatal pulmonary embolism in Australia?

Method

Prospective prevalence study using monthly negative surveillance system of all birthing services in Australia (>50 births) – AMOSS. Nominated clinicians and midwives within each maternity unit will be e-mailed a simple tick-box to indicate whether a case occurred or whether there is ‘nothing to report’. If a case arose, the reporting clinician will complete a case form using the secure web-based data system. Only non-identifiable data will be collected.

Surveillance period

January 2010 – December 2013

Case definition

The cases will be all women in Australia identified as having APE using the following definition:

EITHER pulmonary embolism is confirmed using suitable imaging (angiography, computed tomography, echocardiography, magnetic resonance imaging or ventilation-perfusion scan showing a high probability of pulmonary embolism).
OR pulmonary embolism is confirmed at surgery or postmortem
OR a clinician has made a diagnosis of pulmonary embolism with signs and symptoms consistent with PE present, and the patient has received a course of anticoagulation therapy (>1 week duration).

Study size

The study will run initially for two years. The estimated sample size is between 62 and 84 cases based on the experience of the UK Obstetric Surveillance Service, which found an incidence of 1.3 (95%CI 1.1 to 1.5) APE for every 10 000 pregnant women.2

Investigators

AMOSS CHIEF INVESTIGATORS

Professor Elizabeth Sullivan, Principal Investigator AMOSS, Professor of Public Health, Assistant Deputy Vice Chancellor, University of Technology Sydney and Conjoint Professor, UNSW Medicine, New South Wales

Professor David Ellwood, CI AMOSS, Director of Maternal-Fetal Medicine, Professor of Obstetrics & Gynaecology, Deputy Head of School Research, Gold Coast Health District, Queensland and Deputy Dean, College of Medicine, Australian National University, Australian Capital Territory

Professor Michael Peek, CI AMOSS, Associate Dean, Department of Obstetrics and Gynaecology, Medical School, College of Medicine, Biology and Environment, The Australian National University and Centenary Hospital for Women and Children, Australian Capital Territory

Professor Caroline Homer, CI AMOSS, Professor of Midwifery, Associate Dean: International and Development, Associate Head, WHO Collaborating Centre for Nursing, Midwifery and Health Development, Faculty of Health, University of Technology Sydney, New South Wales

Professor Lisa Jackson Pulver, CI AMOSS, ProVice Chancellor Engagement and Aboriginal and Torres Strait Islander Leadership, Western Sydney University, New South Wales 

Professor Marian Knight, NIHR Professor of Maternal and Child Population Health, National Perinatal Epidemiology Unit (NPEU), University of Oxford, UK.

Dr. Claire McLintock, CI AMOSS, Obstetric physician and haematologist, National Women's Health, Auckland City Hospital, New Zealand

AMOSS ASSOCIATE INVESTIGATORS

Professor Elizabeth Elliott, Professor of Paediatrics & Child Health, The University of Sydney and Australian Perinatal Statistics Unit, The Children's Hospital Westmead New South Wales

Clinical Assoc Professor Nolan McDonnell, Staff Specialist Department of Anaesthesia and Pain Medicine, King Edward Memorial Hospital for Women, Perth Western Australia

Dr Tessa Ho, Trustee, Mary Aitkenhead Ministries

Dr Wendy Pollock, Honorary Research Fellow, La Trobe University/Mercy Hospital for Women, Melbourne Victoria

Associate Professor Yvonne Zurynski, The University of Sydney and Australian Perinatal Statistics Unit, The Children's Hospital Westmead New South Wales

Funding and other support

We gratefully acknowledge our funding partners and participating AMOSS sites.

Initial funding was through a five year project grant (Australian National Health and Medical Research Council NHMRC #510298 2008-2012), which provided support for the first set of AMOSS studies as well as the AMOSS infrastructure.

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.

References

  1. Sullivan, E., B. Hall, and J. King, Maternal deaths in Australia 2003-2005, in Maternal Deaths Series no. 3. Cat. no. PER 42. 2008, AIHW National Perinatal Statistics Unit: Sydney.
  2. Knight M. on behalf of UKOSS, Antenatal pulmonary embolism: risk factors, management and outcomes. BJOG: An International Journal of Obstetrics & Gynaecology, 2008. 115: p. 453-461.