When should antibiotics be given to prevent infectious complications after cesarean birth?

People who undergo surgery are at risk of developing infections, which complicate their recovery. In order to prevent these infections and reduce complications, antibiotics are sometimes given as a preventative (or prophylactic) treatment. The antibiotics are generally given approximately 60 minutes before the operation so that adequate tissue concentrations are reached before the skin is cut. For cesarean deliveries however, the effect of the antibiotic on the baby has to be considered, and for this reason antibiotics have been administered to women after the baby’s umbilical cord is clamped. This may not allow for adequate tissue penetration in the mother for the prevention of surgery-related infections; additionally deferring antibiotics may not benefit the newborn.

This review of randomized controlled studies looked at the different timing options for administration of prophylactic antibiotics to prevent infectious complications in women undergoing cesarean delivery. We compared preoperative administration to administration after the cord had been clamped.

The review includes 10 studies (with data from 5041 women). The studies were at a low risk of bias. Antibiotics given to women before cesarean delivery nearly halved the risks of combined infections (43%), endometritis (46%), and wound infection (41%) compared to giving the antibiotics after clamping of the baby’s umbilical. Other maternal infections such as urinary or lung infections were no different between the two groups of women, nor were adverse effects in newborns. High quality evidence shows that preoperative intravenous antibiotic administration decreases postpartum infections and is, therefore, beneficial for the mother. Maternal side effects were not consistently reported. Numbers were limited with respect to information on newborns and any adverse outcomes. Further research may be needed to determine adverse effects on the babies.

Authors' conclusions: 

Based on high quality evidence from studies whose overall risk of bias is low, intravenous prophylactic antibiotics for cesarean administered preoperatively significantly decreases the incidence of composite maternal postpartum infectious morbidity as compared with administration after cord clamp. There were no clear differences in adverse neonatal outcomes reported. Women undergoing cesarean delivery should receive antibiotic prophylaxis preoperatively to reduce maternal infectious morbidities. Further research may be needed to elucidate short- and long-term adverse effects for neonates.

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Background: 

Given the continued rise in cesarean birth rate and the increased risk of surgical site infections after cesarean birth compared with vaginal birth, effective interventions must be established for prevention of surgical site infections. Prophylactic intravenous (IV) antibiotic administration 60 minutes prior to skin incision is recommended for abdominal gynecologic surgery; however, administration of prophylactic antibiotics has traditionally been withheld until after neonatal umbilical cord clamping during cesarean delivery due to the concern for potential transfer of antibiotics to the neonate.

Objectives: 

To compare the effects of cesarean antibiotic prophylaxis administered preoperatively versus after neonatal cord clamp on postoperative infectious complications for both the mother and the neonate.

Search strategy: 

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (1 March 2014) and reference lists of retrieved papers.

Selection criteria: 

Randomized controlled trials (RCTs) comparing maternal and neonatal outcomes following prophylactic antibiotics administered prior to skin incision versus after neonatal cord clamping during cesarean delivery. Cluster-RCTs were eligible for inclusion but none were identified. Quasi-RCT and trials using a cross-over design were not eligible for inclusion in this review. Studies published in abstract form only were eligible for inclusion if sufficient information was available in the report.

Data collection and analysis: 

At least two review authors independently assessed the studies for inclusion, assessed risk of bias, abstracted data and checked entries for accuracy. We assessed the quality of evidence using the GRADE approach.

Main results: 

We included 10 studies (12 trial reports) from which 5041 women contributed data for the primary outcome. The overall risk of bias was low.

When comparing prophylactic intravenous (IV) antibiotic administration in women undergoing cesarean delivery, there was a reduction in composite maternal infectious morbidity (risk ratio (RR) 0.57, 95% confidence interval (CI) 0.45 to 0.72, high quality evidence), which was specifically due to the reduction in endometritis (RR 0.54, 95% CI 0.36 to 0.79, high quality evidence) and wound infection (RR 0.59, 95% CI 0.44 to 0.81, high quality evidence) in those that received antibiotics preoperatively as compared to those who received antibiotics after neonatal cord clamping. There were no clear differences in neonatal sepsis (RR 0.76, 95% CI 0.51 to 1.13, moderate quality evidence).

There were no clear differences for other maternal outcomes such as urinary tract infection (UTI), cystitis and pyelonephritis (moderate quality evidence), respiratory infection (low quality evidence), or any neonatal outcomes. Maternal side effects were not reported in the included studies.

The quality of the evidence using GRADE was high for composite morbidity, endomyometritis, wound infection and neonatal intensive care unit admission, moderate for UTI/cystitis/pyelonephritis and neonatal sepsis, and low for maternal respiratory infection.

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