Risk factors for surgical site infection following caesarean section in England: Results from a multicentre cohort study

Objective To assess the frequency and risk factors for surgical site infection following caesarean section. Design Prospective multicentre cohort study. Setting Fourteen NHS hospitals in England, April to September 2009. Population Women who underwent caesarean section at participating hospitals during designated study periods. Methods Infections that met standard case definitions were identified through active follow up by healthcare staff during the hospital stay, on return to hospital, during midwife home visits and through self-completed patient questionnaires. Main outcome measure Surgical site infection within 30 days of operation. Results Altogether, 9.6% (394/4107) of women in the study developed a postsurgical infection following caesarean section with 0.6% (23/4107) readmitted for treatment of the infection. Being overweight (body mass index [BMI] 25-30 kg/m² odds ratio [OR] 1.6, 95% confidence interval [95% CI] 1.2-2.2) or obese (BMI 30-35 kg/m² OR 2.4, 95% CI 1.7-3.4; BMI > 35 kg/m² OR 3.7, 95% CI 2.6-5.2) were major independent risk factors for infection (compared with BMI 18.5-25 kg/m²). There was a suggestion that younger women, and operations performed by associate specialist and staff grade surgeons had a greater odds of developing surgical site infection with OR 1.9, 95% CI 1.1-3.4 (<20 years versus 25-30 years), and OR 1.6, 95% CI 1.0-2.4 (versus consultants), respectively. Conclusions This study identified high rates of postsurgical infection following caesarean section. Given the number of women delivering by caesarean section in the UK, substantial costs will be incurred as a result of these infections. Prevention of these infections should be a clinical and public health priority.