This is a follow-up to the original pilot study (HS# 2009-7015 at UCI/587-08 at LBMMC). This study is also designed to be a prospective, non-randomized, non-blinded trial of the effects of obesity on adequacy of antimicrobial (cefazolin) concentrations with increased doses (from 2 grams to 3 grams) of preoperative prophylactic antibiotics within adipose tissues at the time of cesarean delivery.