"Women undergo more cesarean sections each year in the United States than any other major surgery with the procedure carrying a significant rate of infection at the incision site. A new study from Washington University School of Medicine in St. Louis offers strong guidance on the best way to reduce the infection risk. Rather than prepping patients with iodinealcohol  a common antiseptic combination in Csections  the research indicates that chlorhexidinealcohol is significantly more effective. The researchers argue that the evidence is strong enough to change standard skinprep practices for Csections. The study appears online Feb.  in The New England Journal of Medicine and coincides with a presentation at the Society for MaternalFetal Medicines Annual Meeting in Atlanta. One of the biggest complications of surgery and of Csections in particular is infection said first author Methodius G. Tuuli MD assistant professor of obstetrics and gynecology. For a new mother who needs to care for her baby  which is stressful even when all things are equal  having an infection can really impair her ability to do that. We are very interested in clarifying the best ways to prevent these infections reducing the burden on the patients on their infants and on the healthcare system as a whole. An estimated . million women in the U.S. delivered their babies by Csection in  with surgicalsite infections complicating  to  percent of those deliveries. The average cost of treating those cesareanrelated infections in the hospital is  and may be much higher for severe infections. The research shows that patients in the chlorhexidinealcohol group developed significantly fewer infections than patients in the iodinealcohol group. Those who received the chlorhexidinealcohol combination had a  percent infection rate which is nearly half that of the patients who received the iodinealcohol combination  . percent. The clinical trial included  patients who underwent cesarean sections at BarnesJewish Hospital from  to . Of  patients randomly assigned to receive the chlorhexidinealcohol combination  developed an infection at the site of the surgery within  days of the procedure. Of  patients who randomly received the iodinealcohol combination  developed a surgicalsite infection. The investigators pointed out that all other standard procedures for reducing the risk of infection after surgery including giving preventive antibiotics beforehand were the same in both groups. Studies of other types of surgeries also have suggested the superiority of chlorhexidine over iodine in preventing infection. But according to Tuuli the unique circumstances of a Csection  that bacteria come from both skin and vagina and that a womans immune system is altered during pregnancy  mean the results of these studies may not apply. In addition past trials comparing antiseptics before surgery included relatively few participants and often compared a chlorhexidinealcohol combination with iodine alone. These studies could not determine whether the worse performance of iodine alone was due to the chlorhexidine the alcohol or the combination. Although the new study was conducted at only one hospital the researchers said the patient population was racially diverse and that more than  percent received public insurance. Tuuli and his colleagues also pointed out that the superiority of the chlorhexidinealcohol combination was consistent whether the Csection was scheduled or unscheduled whether or not the patient was obese whether staples or sutures were used to close the wound and whether the patient had chronic medical conditions including diabetes. Highlighting the significance of the findings the studys senior author George A. Macones MD the Mitchell and Elaine Yanow Professor and head of the Department of Obstetrics and Gynecology said This study is a tremendous addition to the literature on preventing surgicalsite infections after cesarean. There are few circumstances when a single study should change our practice. But based on the biological plausibility and the striking reduction in surgicalsite infections with chlorhexidine this is one of those circumstances.  This work was supported by a Womens Reproductive Health Research Career Development grant from the Eunice Kennedy Shriver National Institute of Child Health and Human Development of the National Institutes of Health NIH grant number KHD and by the Department of Obstetrics and Gynecology at Washington University School of Medicine in St. Louis. Tuuli MG Liu J Stout MJ Martin S Cahill AG Odibo AO Colditz GA Macones GA. A randomized trial comparing skin antiseptic agents at cesarean delivery. New England Journal of Medicine. Feb.  . Washington University School of Medicines  employed and volunteer faculty physicians also are the medical staff of BarnesJewish and St. Louis Childrens hospitals. The School of Medicine is one of the leading medical research teaching and patientcare institutions in the nation currently ranked sixth in the nation by U.S. News  World Report. Through its affiliations with BarnesJewish and St. Louis Childrens hospitals the School of Medicine is linked to BJC HealthCare."