Bird flu during pregnancy: women died in 90% of cases

The vast majority of women who contract bird flu during pregnancy and their unborn baby will die from the virus, according to a new study. And the findings stress the importance of early inclusion of pregnant women in public health vaccination programs during pandemics.

The research, led by Murdoch Children’s Research Institute (MCRI), recommends that as human cases of avian influenza viruses A (H5N1 and H5N2) increase, an awareness around the vulnerability of pregnant women to a new pandemic is urgently needed. The systematic review of more than 1,500 research papers examined 30 reported cases of bird flu in women who were pregnant across four countries.

Published in Emerging Infectious Diseases, the review found that women died in 90 per cent of cases when infected with bird flu during pregnancy with almost all their babies dying with them. Of the small number of babies who survived, 80 per cent were born prematurely.

MCRI Dr Rachael Purcell said the inclusion of pregnant women as early as possible in pandemic planning must be a key priority. “Increasing numbers of human cases of avian influenza associated with outbreaks in birds and mammals raises concerns about the possibility of another pandemic in the near future,” she said.

“Despite being a high-risk population, pregnant women are often excluded from vaccine trials, priority access to therapeutics and delayed entry into public health vaccination programs. A paradigm shift is required to routinely include pregnant women in pandemic preparedness programs to avoid preventable deaths. “This could be achieved through utilising the capacity of existing surveillance systems such as the Global Vaccine Data Network or the Vaccine Safety Datalink, the planning of vaccine trials to include the complex needs of pregnancy, and the upscaling of adverse reaction detection systems to identify risks in pregnant women.”

MCRI Professor Jim Buttery said during pandemics vulnerable populations were often at high risk of severe disease and death.

“Pregnant women have experienced high death and critical illness rates during the influenza and SARS-CoV-2 pandemics and the Ebola epidemic,” he said. Global efforts are needed to proactively recognise and mitigate this risk prior to the onset of a pandemic, rather than as a reactive process once a health crisis has started.

“Ethical pandemic preparedness to avoid preventable deaths requires early inclusion of vulnerable populations in vaccine development, monitoring and trials. A pregnancy focused research agenda should be developed and facilitated by medical review boards, regulators and policy makers.”

MCRI’s research team welcomed the Federal Government’s $95 million investment to help prepare against H5N1. Australia is the only continent that remains free of the deadliest bird flu strain.

Read about the bird flu situation in Australia, what to do if you travel overseas and the importance of getting an annual influenza vaccine.

Researchers from the University of Melbourne, The Royal Children’s Hospital, Monash Health and Monash University also contributed to the findings.

Publication: Purcell R, Giles ML, Crawford NW and Buttery J. ‘Systematic Review of Avian Influenza Virus Infection and Outcomes During Pregnancy,’ Emerging Infectious Diseases. DOI: 10.3201/eid3101.241343

MCRI communication