Prophylactic use of cefazolin in monitored obstetric patients undergoing cesarean section.

Prophylactic cefazolin was evaluated in high-risk obstetric patients who had invasive fetal monitoring and subsequent cesarean section. A three-dose regimen of either cefazolin or placebo was administered randomly in a double-blind manner to 93 patients, 48 receiving cefazolin and 45 placebo, with the first dose given when the cord was clamped. In the placebo group, 51% of the patients were treated for endomyometritis compared to 29% in the cefazolin group. The incidence of urinary tract and wound infections was similar in the 2 groups. One patient in the active drug group was diagnosed as having septic pelvic thrombophlebitis and received multiple antibiotics and heparin before she recovered. One patient in the placebo group required triple antibiotic therapy. Operation to control infection was not required in any patients and there were no maternal deaths. The cefazolin patients had fewer degree-hours of morbidity as calculated by the quantitative fever index (P less than 0.002). The perioperative use of cefazolin was efficacious in reducing the incidence of endomyometritis, but did not prevent serious postoperative pelvic infection.