Kim Boggess, MD - Division of Maternal Fetal Medicine
The cesarean section optimal antibiotic prophylaxis (C/SOAP) study is a large multi-center randomized clinical trial designed to evaluate the effectiveness and safety of azithromycin-based extended-spectrum antibiotic prophylaxis (azithromycin plus standard narrow-spectrum cephalosporin) compared to cephalosporin alone prior to surgical incision to prevent post-cesarean infection. Azithromycin but not standard cephalosporin is effective against other pathogens, especially Ureaplasma, a strong risk factor for post-cesarean endometritis when present in the chorioamnion, and the most common isolate from wound infections. Based on our preliminary studies, extended prophylaxis may effectively lower the risk of post-cesarean infection compared to standard cephalosporin alone. We will enroll women at high risk for post-cesarean infection despite standard prophylaxis - those undergoing a non-elective cesarean during labor or after membrane rupture. These women face a high likelihood of ascending colonization and infection with ureaplasmas from the lower genital tract. During the 4-year project period, 3 collaborating perinatal centers, recognized nationally for their expertise in the conduct of multi-center clinical trials, will randomize 2000 women undergoing unscheduled cesarean to either 500mg of intravenous azithromycin or identical placebo initiated prior to surgery; concurrently, both groups will also receive standard single-dose cefazolin prophylaxis (or clindamycin for cephalosporin allergy). Women will be followed-up for at least 30 days according to CDC recommendations for ascertaining surgical site infections. Neonatal outcomes will also be recorded.