Optimal timing of prophylactic antibiotic for cesarean delivery: a randomized comparative study

Cesarean delivery is associated with a significantly higher postoperative infection rate than that following vaginal birth and other surgical procedures. This study compared whether antibiotic prophylaxis administered preoperatively was more effective in preventing infectious morbidity following cesarean delivery than administration at cord clamping.

In a randomized comparative trial, 953 women with a period of gestation of more than 34 weeks, scheduled to have cesarean section, were randomly assigned to the prophylactic single-dose antibiotic administration either preoperatively (study group) or at cord clamping (control group). Primary outcome measure was postoperative maternal infectious morbidity and secondary outcome measures were neonatal complications, and postoperative maternal hospital stay and stay of neonates in the neonatal intensive care unit.

Wound complications in the form of indurations, erythema and discharge, were significantly fewer in the study group as compared to the control group (10/476 vs 25/477, P = 0.010, conditional maximum likelihood estimate of odds ratio = 0.388 and 95% confidence interval = 0.175-0.805). Women in the study group also had fewer incidents of endomyometritis when compared to the control group (1.47% vs 3.56%; P = 0.041; conditional maximum likelihood estimate of odds ratio = 0.404). There was no significant difference in neonatal outcomes between the two groups. Mean postoperative stay of mothers in hospital was significantly shorter in the study group (P = 0.009, 95% confidence interval = -0.368 to -0.052) but neonatal intensive care unit stay of neonates was similar in both groups.

Administration of prophylactic antibiotic at 30-60 min before skin incision resulted in better maternal outcome when infectious morbidity and postoperative hospital stay were concerned, without influencing the neonatal outcome.