Risk factors for surgical site infection after low transverse cesarean section.

BACKGROUND Independent risk factors for surgical site infection (SSI) after cesarean section have not been well documented, despite the large number of cesarean sections performed and the relatively common occurrence of SSI. OBJECTIVE To determine independent risk factors for SSI after low transverse cesarean section. DESIGN Retrospective case-control study. SETTING Barnes-Jewish Hospital, a 1,250-bed tertiary care hospital. PATIENTS A total of 1,605 women who underwent low transverse cesarean section during the period from July 1999 to June 2001. METHODS Using the International Classification of Diseases, Ninth Revision, Clinical Modification diagnosis codes for SSI or wound complication and/or data on antibiotic use during the surgical hospitalization or at readmission to the hospital or emergency department, we identified potential cases of SSI in a cohort of patients who underwent a low transverse cesarean section. Cases of SSI were verified by chart review using the definitions from the Centers for Disease Control and Prevention's National Nosocomial Infections Surveillance System. Control patients without SSI or endomyometritis were randomly selected from the population of patients who underwent cesarean section. Independent risk factors for SSI were determined by logistic regression. RESULTS SSIs were identified in 81 (5.0%) of 1,605 women who underwent low transverse cesarean section. Independent risk factors for SSI included development of subcutaneous hematoma after the procedure (adjusted odds ratio [aOR], 11.6 [95% confidence interval [CI], 4.1-33.2]), operation performed by the university teaching service (aOR, 2.7 [95% CI, 1.4-5.2]), and a higher body mass index at admission (aOR, 1.1 [95% CI, 1.0-1.1]). Cephalosporin therapy before or after the operation was associated with a significantly lower risk of SSI (aOR, 0.2 [95% CI, 0.1-0.5]). Use of staples for skin closure was associated with a marginally increased risk of SSI. CONCLUSIONS These independent risk factors should be incorporated into approaches for the prevention and surveillance of SSI after surgery.