Single-dose trimethoprim-sulfamethoxazole prophylaxis for cesarean section

Antibiotic prophylaxis versus no prophylaxis for preventing infection after cesarean section

BACKGROUND

The single most important risk factor for postpartum maternal infection is cesarean section. Although guidelines endorse the use of prophylactic antibiotics for women undergoing cesarean section, there is not uniform implementation of this recommendation. This is an update of a Cochrane review first published in 1995 and last updated in 2010.

OBJECTIVES

To assess the effects of prophylactic antibiotics compared with no prophylactic antibiotics on infectious complications in women undergoing cesarean section.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (31 July 2014) and reference lists of retrieved papers.

SELECTION CRITERIA

Randomized controlled trials (RCTs) and quasi-RCTs comparing the effects of prophylactic antibiotics versus no treatment in women undergoing cesarean section.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed the studies for inclusion, assessed risk of bias and carried out data extraction. The clinically important primary outcomes were wound infection, endometritis, serious maternal infectious complications and adverse effects on the infant. We presented dichotomous data as risk ratios (RR), with 95% confidence intervals (CIs) and combined trials in meta-analyses. We assessed the quality of evidence using the GRADE approach.

MAIN RESULTS

We identified 95 studies enrolling over 15,000 women. Compared with placebo or no treatment, the use of prophylactic antibiotics in women undergoing cesarean section reduced the incidence of wound infection (RR 0.40, 95% CI 0.35 to 0.46, 82 studies, 14,407 women), endometritis (RR 0.38, 95% CI 0.34 to 0.42, 83 studies, 13,548 women) and maternal serious infectious complications (RR 0.31, 95% CI 0.20 to 0.49, 32 studies, 6159 women). When only studies that included women undergoing an elective cesarean section were analyzed, there was also a reduction in the incidence of wound infections (RR 0.62, 95% CI 0.47 to 0.82, 17 studies, 3537 women) and endometritis (RR 0.38, 95% CI 0.24 to 0.61, 15 studies, 2502 women) with prophylactic antibiotics. Similar estimates of effect were seen whether the antibiotics were administered before the cord was clamped or after. The effect of different antibiotic regimens was studied and similar reductions in the incidence of infections were seen for most of the antibiotics and combinations.There were no data on which to estimate the effect of maternal administration of antibiotics on infant outcomes. No studies systematically collected and reported on adverse infant outcomes nor the effect of antibiotics on the developing infant immune system. No studies reported on the incidence of oral candidiasis (thrush) in babies. Maternal adverse effects were also rarely described.We judged the evidence for antibiotic treatment compared with no treatment to be of moderate quality; most studies lacked an adequate description of methods and were assessed as being at unclear risk of bias.

AUTHORS' CONCLUSIONS

The conclusions of this review support the recommendation that prophylactic antibiotics should be routinely administered to all women undergoing cesarean section to prevent infection. Compared with placebo or no treatment, the use of prophylactic antibiotics in women undergoing cesarean section reduced the incidence of wound infection, endometritis and serious infectious complications by 60% to 70%. There were few data on adverse effects and no information on the effect of antibiotics on the baby, making the assessment of overall benefits and harms difficult. Prophylactic antibiotics given to all women undergoing elective or non-elective cesarean section is beneficial for women but there is uncertainty about the consequences for the baby.

Current debate on the use of antibiotic prophylaxis for caesarean section

Caesarean delivery is frequently complicated by surgical site infections, endometritis and urinary tract infection. Most surgical site infections occur after discharge from the hospital, and are increasingly being used as performance indicators. Worldwide, the rate of caesarean delivery is increasing. Evidence-based guidelines recommended the use of prophylactic antibiotics before surgical incision. An exception is made for caesarean delivery, where narrow-range antibiotics are administered after umbilical cord clamping because of putative neonatal benefit. However, recent evidence supports the use of pre-incision, broad-spectrum antibiotics, which result in a lower rate of maternal morbidity with no disadvantage to the neonate.

Antibiotic prophylaxis versus no prophylaxis for preventing infection after cesarean section

BACKGROUND

The single most important risk factor for postpartum maternal infection is cesarean section. Routine prophylaxis with antibiotics may reduce this risk and should be assessed in terms of benefits and harms.

OBJECTIVES

To assess the effects of prophylactic antibiotics compared with no prophylactic antibiotics on infectious complications in women undergoing cesarean section.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (May 2009).

SELECTION CRITERIA

Randomized controlled trials (RCTs) and quasi-RCTs comparing the effects of prophylactic antibiotics versus no treatment in women undergoing cesarean section.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed the studies for inclusion, assessed risk of bias and carried out data extraction.

MAIN RESULTS

We identified 86 studies involving over 13,000 women. Prophylactic antibiotics in women undergoing cesarean section substantially reduced the incidence of febrile morbidity (average risk ratio (RR) 0.45; 95% confidence interval (CI) 0.39 to 0.51, 50 studies, 8141 women), wound infection (average RR 0.39; 95% CI 0.32 to 0.48, 77 studies, 11,961 women), endometritis (RR 0.38; 95% CI 0.34 to 0.42, 79 studies, 12,142 women) and serious maternal infectious complications (RR 0.31; 95% CI 0.19 to 0.48, 31 studies, 5047 women). No conclusions can be made about other maternal adverse effects from these studies (RR 2.43; 95% CI 1.00 to 5.90, 13 studies, 2131 women). None of the 86 studies reported infant adverse outcomes and in particular there was no assessment of infant oral thrush. There was no systematic collection of data on bacterial drug resistance. The findings were similar whether the cesarean section was elective or non elective, and whether the antibiotic was given before or after umbilical cord clamping. Overall, the methodological quality of the trials was unclear and in only a few studies was it obvious that potential other sources of bias had been adequately addressed.

AUTHORS' CONCLUSIONS

Endometritis was reduced by two thirds to three quarters and a decrease in wound infection was also identified. However, there was incomplete information collected about potential adverse effects, including the effect of antibiotics on the baby, making the assessment of overall benefits and harms complicated. Prophylactic antibiotics given to all women undergoing elective or non-elective cesarean section is clearly beneficial for women but there is uncertainty about the consequences for the baby.

WITHDRAWAN. Antibiotic prophylaxis for cesarean section

BACKGROUND

The single most important risk factor for postpartum maternal infection is cesarean delivery.

OBJECTIVES

The objective of this review was to assess the effects of prophylactic antibiotic treatment on infectious complications in women undergoing cesarean delivery.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group trials register (January 2002) and the Cochrane Controlled Trials Register (The Cochrane Library, Issue 4, 2001).

SELECTION CRITERIA

Randomized trials comparing antibiotic prophylaxis or no treatment for both elective and non-elective cesarean section.

DATA COLLECTION AND ANALYSIS

Two reviewers assessed trial quality and extracted data.

MAIN RESULTS

Eighty-one trials were included. Use of prophylactic antibiotics in women undergoing cesarean section substantially reduced the incidence of episodes of fever, endometritis, wound infection, urinary tract infection and serious infection after cesarean section. The reduction in the risk of endometritis with antibiotics was similar across different patient groups: the relative risk (RR) for endometritis for elective cesarean section (number of women = 2037) was 0.38 (95% confidence interval (CI) 0.22 to 0.64); the RR for non-elective cesarean section (n = 2132) was 0.39 (95% CI 0.34 to 0.46); and the RR for all patients (n = 11,937) was 0.39 (95% CI 0.31 to 0.43). Wound infections were also reduced: for elective cesarean section (n = 2015) RR 0.73 (95% CI 0.53 to 0.99); for non-elective cesarean section (n = 2780) RR 0.36 95% CI 0.26 to 0.51]; and for all patients (n = 11,142) RR 0.41 (95% CI 0.29 to 0.43).

AUTHORS' CONCLUSIONS

The reduction of endometritis by two thirds to three quarters and a decrease in wound infections justifies a policy of recommending prophylactic antibiotics to women undergoing elective or non-elective cesarean section.

Timing of perioperative antibiotics for cesarean delivery: a metaanalysis

OBJECTIVE

The purpose of this study was to summarize the available evidence on timing of perioperative antibiotics for cesarean delivery.

STUDY DESIGN

We searched the literature for studies that compare prophylactic antibiotics for cesarean delivery that are given before the procedure vs at cord clamping. Only randomized controlled trials were included.

RESULTS

Preoperative administration significantly reduced the risk of postpartum endometritis (relative risk [RR], 0.47; 95% CI, 0.26-0.85; P = .012) and total infectious morbidity (RR, 0.50; 95% CI, 0.33-0.78; P = .002). There was a trend toward lower risk of wound infection (RR, 0.60; 95% CI, 0.30-1.21; P = .15). Preoperative administration of antibiotics did not significantly affect suspected neonatal sepsis that requires a workup (RR, 1; 95% CI, 0.70-1.42), proven sepsis (RR, 0.93; 95% CI, 0.45-1.96), or neonatal intensive care unit admissions (RR, 1.07 95% CI, 0.51-2.24). There was no significant heterogeneity between the randomized controlled trials.

CONCLUSION

There is strong evidence that antibiotic prophylaxis for cesarean delivery that is given before skin incision, rather than after cord clamping, decreases the incidence of postpartum endometritis and total infectious morbidities, without affecting neonatal outcomes.

Antibiotic prophylaxis for cesarean section

BACKGROUND

The single most important risk factor for postpartum maternal infection is Cesarean delivery.

OBJECTIVES

The objective of this review was to assess the effects of prophylactic antibiotic treatment on infectious complications in women undergoing Cesarean delivery.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group trials register and the Cochrane Controlled Trials Register.

SELECTION CRITERIA

Randomised trials comparing antibiotic prophylaxis or no treatment for both elective and non-elective Cesarean section.

DATA COLLECTION AND ANALYSIS

Two reviewers assessed trial quality and extracted data.

MAIN RESULTS

Sixty-six trials were included. Use of prophylactic antibiotics in women undergoing Cesarean section substantially reduced the incidence of episodes of fever, endometritis, wound infection, urinary tract infection and serious infection after Cesarean section. The reduction in the risk of endometritis with antibiotics was similar across different patient groups. The relative risk for elective Cesarean section was 0.24, 95% confidence interval 0.11 to 0.48. The relative risk for non-elective Cesarean section was 0.30, 95% confidence interval 0.25 to 0.35. The relative risk for undefined or all patients together was 0.29, 95% confidence interval 0.26 to 0.33. Despite the large number of trials, different populations and different antibiotic regimens, there was no statistically significant heterogeneity.

REVIEWER'S CONCLUSIONS

The reduction of endometritis by two thirds to three quarters justifies a policy of administering prophylactic antibiotics to women undergoing elective or non-elective Cesarean section.

Antibiotic prophylaxis in cesarean section

Several controversies exist regarding the use of antibiotic prophylaxis in cesarean section. Studies have investigated effectiveness, choice of drug, timing, duration, and appropriate route of administration. Efficacy of antibiotic prophylaxis in preventing postoperative endometritis in certain high-risk patients has been well documented. Factors identifying patients at high risk for endometritis include: indigent socioeconomic status, labor prior to cesarean section, rupture of chorioamniotic membranes, and number of vaginal examinations. Although many different antibiotics have been tested, no particular regimen has been found to be superior. Administration of antibiotics after cord clamping reduces the risk of fetal exposure without compromising maternal risk of endometritis. A single dose of ampicillin or a first-generation cephalosporin (e.g., cefazolin or cephalothin sodium) given intravenously provides adequate prophylaxis. No additional benefit has been demonstrated with the use of multiple-dose regimens.

Single-dose cefazolin prophylaxis for cesarean section

In a prospective, randomized trial, the efficacy of a single-dose, first-generation, long-acting cephalosporin was compared with a three-dose regimen in a group of 100 women undergoing cesarean section who were at high risk for postoperative febrile morbidity. Fifty women received a single 1 gm intravenous dose of cefazolin and 50 received 1 gm of the drug followed by two additional doses, 8 hours apart, to complete a three-dose regimen. Another 50 women, considered to be at low risk for postoperative febrile morbidity, were not given antibiotic prophylaxis. Outcomes of febrile morbidity (18% vs 12%) and particularly morbidity caused by endometritis (6% vs 8%, respectively) were similar for single-dose and three-dose groups. In the untreated low-risk group there were no cases of endometritis and the febrile morbidity was comparable to that of the prophylactically treated groups (14% vs 15%). Single-dose cefazolin prophylaxis appears to be comparable to multidose prophylaxis in reducing febrile morbidity after cesarean section.

Prophylactic antibiotics for cesarean delivery: a simple cost-effective strategy for prevention of postoperative morbidity

Postoperative endomyometritis is the most common complication associated with cesarean delivery. The frequency of endomyometritis varies from 5% to 85% (mean 35% to 40%), depending on the socioeconomic characteristics of the patient population and the indication for abdominal delivery. In women undergoing cesarean section after extended duration of labor and ruptured membranes, the use of prophylactic antibiotics has been consistently effective in decreasing the frequency of endomyometritis. A single dose of antibiotic administered after the umbilical cord is clamped provides a degree of prophylaxis comparable to that achieved with two- and three-dose regimens. There is no evidence that the newer extended-spectrum cephalosporins or penicillins are better for prophylaxis than ampicillin or a first-generation cephalosporin. Administration of antibiotics by intraoperative irrigation is an acceptable, but not superior, alternative to systemic antibiotic administration. Prophylactic antibiotics alter the vaginal flora after operation, but to date harmful clinical effects have not occurred as a result of such alteration.

Changing concepts in obstetric antibiotic prophylaxis

The evolution of antibiotic prophylaxis in cesarean section is traced from the discovery of sulfa compounds in the 1940s to the present. Prolonged courses of antibiotics, initiated before the surgical incision, have given way to shorter, three-dose and even single-dose regimens administered after clamping of the umbilical cord. Several factors have been proposed to help identify patients at greatest risk of infection. Guidelines for antibiotic prophylaxis are reviewed. The effects of antibiotics on host flora are described, and the implications of bacterial resistance for selection of a prophylactic agent, particularly with respect to induction of the Richmond-Sykes type I beta-lactamase enzyme, are discussed.