Pregnant women were urged to get their annual flu jab yesterday as research showed they have a five times greater risk of a stillbirth if they are admitted to hospital with swine flu.

The study, by the National Perinatal Epidemiology Unit at the University of Oxford, recorded seven stillbirths and three deaths of babies shortly after birth among 256 mothers infected with swine flu between September 2009 and January 2010.

In 2009, 36.6 per cent of healthy pregnant women had the jab, as did 56.6 per cent of pregnant women with other health conditions. Louise Silverton, deputy general secretary of the Royal College of Midwives, said: "This shows the importance of vaccinating all pregnant women."