Study of Effectiveness and Safety of Azithromycin-based Extended-spectrum Prophylaxis to Prevent Post Cesarean Infection

The Cesarean Section Optimal Antibiotic Prophylaxis (C/SOAP) study is a large pragmatic multi-center randomized clinical trial designed to evaluate the comparative effectiveness and safety of azithromycin-based extended-spectrum antibiotic prophylaxis (azithromycin plus standard narrow-spectrum cephalosporin) relative to standard single-agent cephalosporin (preferably prior to surgical incision) to prevent post-cesarean infection. Hypothesis: Compared to narrow-spectrum prophylaxis (i.e. cefazolin alone, or clindamycin if cephalosporin allergy) prior to surgical incision, the addition of extended-spectrum prophylaxis (azithromycin + cefazolin) reduces the incidence of post-cesarean infection.