One in 10 women who has a baby by Caesarean section suffers an infection after surgery, with the highest rates among those who are obese, a study reveals.

About six per cent of the infections are so serious that hospital treatment is needed. The study of 4,100 women by the Health Protection Agency is the first to link obesity with C-section problems.

The study is published in the British Journal of Obstetrics & Gynaecology.