Risk Factors for Postcesarean Surgical Site Infection THACH SON TRAN, MD, PhD, SILOM JAMULITRAT, MD, VIRASAKDI CHONGSUVIVATWONG, MD, PhD, AND ALAN GEATER, PhD Objective: To determine postcesarean complications and identify independent risk factors for surgical site infection. Methods: We studied a cohort of 969 women delivered by cesarean between May and August 1997. Infections were determined by examinations during ward rounds, reviews of laboratory results, and follow-up for 30 days after discharge. Risk factors were identified by multiple logistic regression. Results: Surgical complications were rare. There were febrile morbidity and infection complications in 16.2% and 12.4% of subjects, respectively. Eighty-five subjects had 95 surgical site infections (9.8%), and seven risk factors were independently associated with infection. Risk factors in- cluded preoperative remote infection (adjusted odd ratio [OR] 16.5, 95% confidence interval [CI] 2.1, 128.3); chorioam- nionitis (OR 10.6, 95% CI 2.1, 54.2); maternal preoperative condition (OR 5.3 for those with severe systemic disease [American Society of Anesthesiologists score >3], 95% CI 1.2, 24.0); preeclampsia (OR 2.3, 95% CI 1.1, 4.9); higher body mass index (OR 2.0 for every five-unit increment, 95% CI 1.3, 3.0); nulliparity (OR 1.8, 95% CI 1.1, 3.2); and increased surgical blood loss (OR 1.3 for every 100-mL increment, 95% CI 1.1, 1.5). Conclusion: Host susceptibility and existing infections were important predictors of surgical site infection after cesarean delivery. Further intervention should target this high-risk group to reduce the clinical effect of surgical site infection. (Obstet Gynecol 2000;95:367–71. © 2000 by The American College of Obstetricians and Gynecologists.) Maternal morbidity related to infections after cesarean was eight-fold higher than after vaginal delivery. 1 Sur- gical site infection is defined operationally as infection involving the abdominal incision or the uterus. 2,3 Total cost in the United States, including indirect expenses related to this morbidity, could exceed $10 billion annually. 4 Reported rates of postcesarean surgical site infection vary greatly, from 0.3% in Turkey, 5 11.6% in Brazil, 6 to 18.3% in Saudi Arabia. 7 Despite numerous investiga- tions, there is disagreement about risk factors of surgi- cal site infection after cesarean delivery. Many factors affect infection rates in different settings. Confounding variables were not sufficiently controlled in many of those studies. Therefore, we conducted this prospective study to determine postoperative complications and to identify risk factors for surgical site infection after cesarean, by multivariate analysis. A better understand- ing of predictors might improve infection control by reducing clinical effects of postcesarean infections. Materials and Methods We prospectively studied a cohort of 969 women who had cesareans at Hungvuong Hospital in Ho Chi Minh City, Vietnam. It is a 450-bed, tertiary care obstetric and gynecologic hospital with an average of 1300 deliveries and 350 major operations per month. It serves the population of 2.5 million women in Ho Chi Minh City and is a referral center for 18 district hospitals and the obstetrics and gynecology departments of other hospi- tals in the city. From May to August 1997, all women who had cesareans were recruited. The principal investigator visited each postoperative ward twice weekly and col- lected all pertinent data. Demographic information, putative factors, and surgical indications were re- corded. Host-related variables included age, residence, parity, body mass index (BMI), preoperative stay, exist- ing comorbidities, prior amniocentesis, labor induction, rupture of membrane duration, and preoperative con- dition. Surgery-related variables included emergency nature of the operation, cesarean hysterectomy, surgical From the Hungvuong Obstetric and Gynecological Hospital, Ho Chi Minh City, Vietnam. Dr. Nguyen Thi Thuy, Director of Hungvuong Hospital gave permis- sion to conduct this study in Hungvuong Hospital. Financial support was provided by Special Program of Research, Development and Research Training in Human Reproduction (World Health Organization). Epidemiology Unit is supported by Thailand Research Fund. 367 VOL. 95, NO. 3, MARCH 2000 0029-7844/00/$20.00 PII S0029-7844(99)00540-2