Timing of prophylactic antibiotic at cesarean section: a double-blinded, randomized trial

The purpose was to determine the effect of the timing of prophylactic antibiotics for cesarean section on post-operative infectious complications.

This was a prospective, double-blinded, randomized controlled trial in which patients were randomized to receive cefazolin or clindamycin either before skin incision or after cord clamp. The primary outcome was maternal infectious morbidity at 6 weeks postpartum, a composite infectious outcome, which included endometritis, urinary tract infection, wound infection and pneumonia.

Data on 896 women were analyzed; 449 randomized to skin incision, 447 to cord clamp. Postpartum infections were seen in a total of 8.4% of patients. Timing of antibiotic administration did not significantly affect any maternal postpartum infection rates or selected neonatal outcomes.

Our results suggest that, in a largely non-laboring population, the timing of prophylactic antibiotic administration does not impact post-operative infectious complications of the mother. Despite being one of the largest randomized controlled trials to address this question, our study still lacked sufficient power to make definitive conclusions.