A study to be published in the British Medical Journal (BMJ) today has found 11 percent of pregnant women admitted to intensive care units (ICU) with 2009 A/H1N1 (swine flu) died, with 12 percent of babies born to them dying from complications. None of the mothers had been immunised against seasonal flu.
The research is the first of its kind to study this area of the 2009 swine flu pandemic, the first such outbreak to occur in the era of modern obstetric and intensive care management.
The authors, led by Dr Ian Seppelt from the Australian and New Zealand Intensive Care (ANZIC) Influenza Investigators in collaboration with the Australasian Maternity Outcomes Surveillance System, assessed the data relating to all women with swine flu who were pregnant or who had given birth in the last 28 days and were admitted to an ICU in Australia or New Zealand between 1 June and 31 August 2009.
During the study period, 209 women of child-bearing age (15 to 44) were admitted to an ICU with confirmed swine flu. Sixty-four of these (30.6 percent) were either pregnant or had recently given birth and 57 were admitted to an ICU in Australia and seven to an ICU in New Zealand.
Dr Seppelt said the study found women with swine flu who were more than 20 weeks pregnant were 13 times more likely to be admitted to hospital with a critical illness.
"It has already been established that pregnant women are at a higher risk of developing influenza complications," Dr Seppelt said.
"The effects of influenza during pregnancy have been noted in previous pandemics, particularly the increased morbidity in pregnant women compared with the general population.