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/m(2) odds ratio [OR] 1.6, 95% confidence interval [95% CI] 1.2-2.2) or obese (BMI 30-35 kg/m(2) OR 2.4, 95% CI 1.7-3.4; BMI > 35 kg/m(2) OR 3.7, 95% CI 2.6-5.2) were major independent risk factors for infection (compared with BMI 18.5-25 kg/m(2)). 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.