The investigators propose the conduction of a prospective, randomized, double-blinded clinical trial to evaluate an alternative prophylactic regimen for the prevention of surgical site infection in women who are obese and have been laboring prior to their Cesarean section. This study is to be conducted by the Department of Obstetrics & Gynecology at John Sealy Hospital at the University of Texas Medical Branch in Galveston, Texas. The intervention being studied will be the administration of cephalexin and metronidazole post-operatively for 48 hours. The primary outcome measure will be surgical site infection (including superficial or deep incisional surgical site infection, endometritis, and other related infections, such as septic pelvic thrombophlebitis and abdominal or pelvic abscess) in the post-operative period.