The purpose of this study is to evaluate if preoperative antibiotics, followed by 48 hour course of broad spectrum antibiotics prevents wound infection complications in patients that are obese who undergo cesarean section. Standard antibiotic prophylaxis in all weight women undergoing cesarean section is cefazolin prior to skin incision. It is the hypothesis that a prolonged, 48 hour course of broad spectrum antibiotics that are suited to prevent growth of normal vaginal flora will decrease the rate of surgical site infection in obese patients that are at a greatly increased risk of postoperative infections complications.

We propose the conduction of a prospective, randomized, double-blinded clinical trial to evaluate an alternative prophylactic regimen for the prevention of surgical site infection. This study is to be conducted by the Department of Obstetrics at University Hospital. The intervention being studied will be the continuation of cephalexin and metronidazole for 48 hours. The primary outcome measure will be the development of infectious morbidity, including wound infection and endometritis, in the postoperative period.

In order to most effectively and accurately analyze our primary and secondary research outcomes, the investigators will standardize our surgical operation techniques in all ways feasible. These recommendations will be in concordance with American College of Obstetrics and Gynecology recommendations, as those generally accepted in the medical literature. All patients will undergo surgery in the same small group of HEPA filtration and positive air pressure operating rooms. Appropriate limitations on number of surgeons and assistants scrubbed for surgery as well as general OR traffic will be enforced. Patients will undergo hair clipping of the incision site when appropriate. Chlorhexidine skin decontamination will be the standard surgical site preparation. An antimicrobial, adhesive drape will be used. Prior to skin incision, cefazolin will be administered.

All patients to be considered for recruitment to this study will be undergoing delivery at University Hospital. Patients with an elevated BMI > 30 kg/m2 who undergo cesarean section will be considered for randomization either prior to delivery or in the first 7 hours after delivery, to accommodate the need for the first dose of study medication or placebo 8 hours after surgery. Only patients who agree to inclusion after informed consent will be randomized per protocol.

Inclusion Criteria:

• BMI > 30kg/m*2
• Delivery via cesarean section
• consent to participate
• age 13 or older

Exclusion Criteria:

• known immunodeficiency syndromes
• non-English speaking
• known allergy to cephalosporins or metronidazole