Pregnant women could be at extra risk of serious complications from swine flu after research showed they were fours times as likely to need hospital treatment than members of the general population with the virus.
A study by the US Centers for Disease Control and Prevention, the American equivalent of the UK Health Protection Agency, looked at 34 confirmed or probable cases of pregnant women infected with H1N1 swine flu.
Researchers found that 11 (32%) of the women were admitted to hospital, four times to rate seen in the general population.
However, some of the difference could be down to doctors erring on the side of caution and admitting pregnant women where they might not with a patient showing similar symptoms, the study said.
But the evidence suggested that pregnant women face an increased risk of complications from swine flu.
This is highlighted by the case of Scottish woman Sharon Pentleton, from Saltcoats, Ayrshire, who was flown to Karolinska University Hospital in Stockholm, Sweden, after she was diagnosed with the disease because no beds were available at the only UK unit capable of treating her.
The 26-year-old is in a stable but critical condition, while having her blood artificially oxygenated by circulating it through a machine.