Antibiotic Prophylaxis Before Surgery Versus After Cord Clamping in Elective Cesarean Delivery - a Double-blind, Prospective, Randomized Placebo-controlled Trial

Background. Perioperative antibiotic prophylaxis during elective cesarean section at term to reduce postoperative maternal infectious morbidity is generally used but may not be efficient based on the available data. Also, the optimal timing of prophylactic antibiotic administration is unclear.

Methods. The investigators compared the effectiveness of cefazolin, administered before skin incision versus after umbilical cord clamping versus placebo in a three-arm randomized trial. The primary endpoint of the study was postoperative infectious morbidity, defined as wound infection, endometritis, or urinary tract infection. Results: The primary outcome was observed in 18/370 women in group 1 (4.9%) and in 14/371 women in group 2 (3.8%), whereas it was noted in 45/371 women in group 3 (12.1%; p<0.001 for group 1 vs. group 3; p<0.001 for group 2 vs. group 3; p<0.001 for group 1 vs. group 2 vs. group 3). The number needed to treat to avoid one primary outcome was 13. Comparing groups 1 and 2, there was no statistically significant difference regarding the primary outcome (p=0.6).

Conclusions. In this prospective, randomized, placebo controlled trial the investigators were able to demonstrate the usefulness of prophylactic cefazolin in elective caesarean section versus placebo, irrespective of the timing of administration, ie before skin incision or after umbilical cord clamping.