Studies

Influenza in pregnancy (ICU Admission)

Background

AMOSS first studied the impact of influenza in pregnancy (leading to intensive care admission) in 2009, when it collaborated with the Australian and New Zealand Intensive Care (ANZIC) Influenza Investigators during the H1N1 pandemic. This population-based cohort study demonstrated that pregnant women, particularly in the second half of pregnancy, were more likely than non pregnant women to develop critical illness associated with 2009 H1N1 influenza. Amongst women who developed critical illness, there were poor outcomes including death for mother or baby.

During 2010, AMOSS and ANZICs continueed this collaborative work when we looked at pregnant women admitted to intensive care as a result of influenza (all subtypes) during 2010. The study extended the research already conducted, and will look further at medical and obstetric management, and maternal and infant outcomes when pregnancy is complicated by Influenza-related critical illness. It studied the impact of immunisation on incidence and severity of influenza in Australia and New Zealand during the 2010 season. Data collection for this second study is complete, with analysis in progress.

Research questions

  1. What is the current incidence of intensive care admissions for pregnant women who have influenza in Australia and New Zealand?
  2. What are the risk factors for severe influenza-related critical illness in pregnancy?
  3. How is influenza in pregnancy managed by medical and obstetric clinicians in the intensive care setting?
  4. What are the outcomes for mother and infants where a woman has been admitted to an intensive care unit in Australia or New Zealand as a result of influenza-related critical illness?

Method

Prospective prevalence study using monthly negative surveillance system of all birthing services in Australia (>50 births) – AMOSS.

On a pregnant woman’s diagnosis with influenza in an intensive care unit, the INFINTE investigators were notified via electronic form and flagging, in addition to completing their own INFINITE flu registry survey. The INFINITE coordinator informed AMOSS, who then contacted the AMOSS data coordinator who completed the AMOSS component of the data collection.

Case definition

All women in Australia and New Zealand identified as:

Admitted to an Intensive Care Unit and subsequently diagnosed with influenza (all subtypes), who were a) pregnant, or who b) had given birth within 42 days of admission to Intensive Care.

Surveillance period

June - December 2010 (Influenza all subtypes study).

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.