Comparative cervical microflora shifts after cefoxitin or cefazolin prophylaxis against infection following cesarean section

Different methods of vaginal preparation before cesarean delivery to prevent postoperative infection: a systematic review and network meta-analysis

OBJECTIVE

Precesarean vaginal antisepsis can benefit pregnant women with ruptured membranes. However, in the general population, recent trials have shown mixed results in reducing postoperative infections. This study aimed to systematically review clinical trials and summarize the most suitable vaginal preparations for cesarean delivery in preventing postoperative infection.

DATA SOURCES

We searched PubMed, Web of Science, Cochrane Library, SinoMed databases, and the ClinicalTrials.gov clinical trials registry for randomized controlled trials and conference presentations (past 20 years, 2003-2022). Reference lists of previous meta-analyses were searched manually. In addition, we conducted subgroup analysis on the basis of whether the studies were conducted in developed or developing countries, whether the membranes were ruptured, and whether patients were in labor.

STUDY ELIGIBILITY CRITERIA

We included randomized controlled trials comparing vaginal preparation methods for the prevention of postcesarean infection with each other or with negative controls.

METHODS

Two reviewers independently extracted data and assessed the risk of bias and the certainty of the evidence. The effectiveness of prevention strategies was assessed by frequentist-based network meta-analysis models. The outcomes were endometritis, postoperative fever, and wound infection.

RESULTS

A total of 23 trials including 10,026 cesarean delivery patients were included in this study. Vaginal preparation methods included 19 iodine-based disinfectants (1%, 5%, and 10% povidone-iodine; 0.4% and 0.5% iodophor) and 4 guanidine-based disinfectants (0.05% and 0.20% chlorhexidine acetate; 1% and 4% chlorhexidine gluconate). Overall, vaginal preparation significantly reduced the risks of endometritis (3.4% vs 8.1%; risk ratio, 0.41 [0.32-0.52]), postoperative fever (7.1% vs 11.4%; risk ratio, 0.58 [0.45-0.74]), and wound infection (4.1% vs 5.4%; risk ratio, 0.73 [0.59-0.90]). With regard to disinfectant type, iodine-based disinfectants (risk ratio, 0.45 [0.35-0.57]) and guanidine-based disinfectants (risk ratio, 0.22 [0.12-0.40]) significantly reduced the risk of endometritis, and iodine-based disinfectants reduced the risk of postoperative fever (risk ratio, 0.58 [0.44-0.77]) and wound infection (risk ratio, 0.75 [0.60-0.94]). With regard to disinfectant concentration, 1% povidone-iodine was most likely to simultaneously reduce the risks of endometritis, postoperative fever, and wound infection.

CONCLUSION

Preoperative vaginal preparation can significantly reduce the risk of postcesarean infectious diseases (endometritis, postoperative fever, and wound infection); 1% povidone-iodine has particularly outstanding effects.

Antepartum Antibiotic Therapy under 34 Weeks of Gestation and Its Impact on Early-Onset Neonatal Infection and Maternal Vaginal Microbiota

The use of prenatal antibiotics should be carefully considered, owing to their potential adverse effects on neonatal outcomes. This study aimed to identify the contributing factors to early-onset neonatal infection and to determine the influence of antepartum antibiotics on women and neonates. This study included 127 pregnant women without obvious intra-amniotic infection on admission, who delivered under 34 weeks of gestation. Information on maternal and neonatal characteristics was obtained from their medical charts. Vaginal swabs were taken from all women on admission. In total, 29 (22.8%) neonates developed early-onset infection. Multivariate analysis revealed that antepartum antibiotics were the most strongly associated factor for early-onset neonatal infection (odds ratio, 11.2; 95% confidence interval, 4.08–31.02). The frequency of early-onset neonatal infection was significantly higher in women who received antibiotic therapy than in those who did not; no significant difference in prolonging their gestation or neonatal morbidities was observed. The prevalence of women who hosted vaginal microorganisms on admission was similar to that in women whose infants subsequently developed early-onset neonatal infection compared with that of women whose infants did not. Among infants of the 40 women who received antepartum antibiotic therapy, 21 developed early-onset infection. Of the women who delivered these 21 infants, 62% (13/21) showed reduced lactobacilli and 43% (9/21) had resistant bacterial strains in their vaginal microbiota at the time of delivery. The use of antepartum antibiotics is the most strongly associated factor in early-onset neonatal infection; it does not prolong gestation and would change the vaginal environment.

Vaginal preparation with different antiseptic solutions before cesarean section for preventing postoperative infections: A systematic review and network meta-analysis

AIMS

We aimed to investigate the effect of various vaginal wash solutions on reducing risks of post-cesarean endometritis, wound infections, fever, and hospital stay duration.

METHODS

Scopus, Web of Science, PubMed, and Cochrane Library were searched for randomized clinical trials that compared different vaginal wash solutions to each other or to "no vaginal cleaning"; without restriction on the age of parturients or site where trials were conducted. We analyzed this frequentist network meta-analysis using the netmeta package in R software version 4.1.2; synthesized data as mean difference or risk ratio with their 95% confidence intervals.

RESULTS

Our network meta-analysis included 29 RCTs with a total sample size of 9311 women undergoing CS. Regarding post-cesarean endometritis, we found that povidone-iodine had the highest significant risk reduction compared to "no vaginal cleaning" (RR = 0.08, 95% CI [0.01, 0.69]). While regarding post-cesarean reduction of wound infection, fever, and hospital stay duration, we found that chlorhexidine 4% (RR = 0.17, 95% CI [0.05, 0.65]), saline 0.9% (RR = 0.12, 95% CI [0.03; 0.48]), and saline 0.9% (MD = -1.29, 95% CI [-2.18; -0.39]), respectively, had the highest significant risk reduction compared to "no vaginal cleaning."

CONCLUSION

Vaginal wash solutions were associated with a significant reduction of post-cesarean endometritis, wound infection, fever, and hospital stay duration. Since povidone-iodine had the highest significant reduction of post-cesarean endometritis, we recommend setting povidone-iodine as the standard practice as pre cesarean vaginal wash solution; consistent practice guidelines of Enhanced Recovery After Surgery (ERAS).

Different classes of antibiotics given to women routinely for preventing infection at caesarean section

BACKGROUND

Caesarean section increases the risk of postpartum infection for women and prophylactic antibiotics have been shown to reduce the incidence; however, there are adverse effects. It is important to identify the most effective class of antibiotics to use and those with the least adverse effects.  OBJECTIVES: To determine, from the best available evidence, the balance of benefits and harms between different classes of antibiotic given prophylactically to women undergoing caesarean section, considering their effectiveness in reducing infectious complications for women and adverse effects on both mother and infant.

SEARCH METHODS

For this 2020 update, we searched Cochrane Pregnancy and Childbirth's Trials Register, ClinicalTrials.gov, the WHO International Clinical Trials Registry Platform (ICTRP) (2 December 2019), and reference lists of retrieved studies.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) comparing different classes of prophylactic antibiotics given to women undergoing caesarean section.  RCTs published in abstract form were also included. We excluded trials that compared drugs with placebo or drugs within a specific class; these are assessed in other Cochrane Reviews. We excluded quasi-RCTs and cross-over trials. Cluster-RCTs were eligible for inclusion but none were identified.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed the studies for inclusion, assessed risk of bias and carried out data extraction. We assessed the certainty of the evidence using the GRADE approach.

MAIN RESULTS

We included 39 studies, with 33 providing data (8073 women). Thirty-two studies (7690 women) contributing data administered antibiotics systemically, while one study (383 women) used lavage and was analysed separately. We identified three main comparisons that addressed clinically important questions on antibiotics at caesarean section (all systemic administration), but we only found studies for one comparison, 'antistaphylococcal cephalosporins (1st and 2nd generation) versus broad spectrum penicillins plus betalactamase inhibitors'.   We found no studies for the following comparisons: 'antistaphylococcal cephalosporins (1st and 2nd generation) versus lincosamides' and 'antistaphylococcal cephalosporins (1st and 2nd generation) versus lincosamides plus aminoglycosides'. Twenty-seven studies (22 provided data) included comparisons of cephalosporins (only) versus penicillins (only). However for this update, we only pooled data relating to different sub-classes of penicillins and cephalosporins where they are known to have similar spectra of action against agents likely to cause infection at caesarean section. Eight trials, providing data on 1540 women, reported on our main comparison, 'antistaphylococcal cephalosporins (1st and 2nd generation) versus broad spectrum penicillins plus betalactamase inhibitors'. We found data on four other comparisons of cephalosporins (only) versus penicillins (only) using systemic administration: antistaphylococcal cephalosporins (1st and 2nd generation) versus non-antistaphylococcal penicillins (natural and broad spectrum) (9 studies, 3093 women); minimally antistaphylococcal cephalosporins (3rd generation) versus non-antistaphylococcal penicillins (natural and broad spectrum) (4 studies, 854 women); minimally antistaphylococcal cephalosporins (3rd generation) versus broad spectrum penicillins plus betalactamase inhibitors (2 studies, 865 women); and minimally antistaphylococcal cephalosporins (3rd generation) versus broad spectrum and antistaphylococcal penicillins (1 study, 200 women). For other comparisons of different classes of antibiotics, only a small number of trials provided data for each comparison, and in all but one case data were not pooled. For all comparisons, there was a lack of good quality data and important outcomes often included few women. Three of the studies that contributed data were undertaken with drug company funding, one was funded by the hospital, and for all other studies the funding source was not reported. Most of the studies were at unclear risk of selection bias, reporting bias and other biases, partly due to the inclusion of many older trials where trial reports did not provide sufficient methodological information. We undertook GRADE assessment on the only main comparison reported by the included studies, antistaphylococcal cephalosporins (1st and 2nd generation) versus broad spectrum penicillins plus betalactamase inhibitors, and the certainty ranged from low to very low, mostly due to concerns about risk of bias, wide confidence intervals (CI), and few events. In terms of the primary outcomes for our main comparison of 'antistaphylococcal cephalosporins (1st and 2nd generation) versus broad spectrum penicillins plus betalactamase inhibitors': only one small study reported sepsis, and there were too few events to identify clear differences between the drugs (risk ratio (RR) 2.37, 95% CI 0.10 to 56.41, 1 study, 75 women, very low-certainty evidence). There may be little or no difference between these antibiotics in preventing endometritis (RR 1.10; 95% CI 0.76 to 1.60, 7 studies, 1161 women; low-certainty evidence). None of the included studies reported on infant sepsis or infant oral thrush. For our secondary outcomes, we found there may be little or no difference between interventions for maternal fever (RR 1.07, 95% CI 0.65 to 1.75, 3 studies, 678 women; low-certainty evidence). We are uncertain of the effects on maternal: wound infection (RR 0.78, 95% CI 0.32 to 1.90, 4 studies, 543 women), urinary tract infection (average RR 0.64, 95% CI 0.11 to 3.73, 4 studies, 496 women), composite adverse effects (RR 0.96, 95% CI 0.09 to 10.50, 2 studies, 468 women), and skin rash (RR 1.08, 95% CI 0.28 to 4.1, 3 studies, 591 women) (all very low certainty evidence). Although maternal allergic reactions were reported by two studies, there were no events. There were no infant outcomes reported in the included studies. For the other comparisons, the results for most outcomes had wide CIs, few studies and few women included. None of the included trials reported on longer-term maternal outcomes, or on any infant outcomes.

AUTHORS' CONCLUSIONS

Based on the best currently available evidence, 'antistaphylococcal cephalosporins' and 'broad spectrum penicillins plus betalactamase inhibitors' may have similar efficacy at caesarean section when considering immediate postoperative infection, although we did not have clear evidence for several important outcomes. Most trials administered antibiotics at or after cord clamping, or post-operatively, so results may have limited applicability to current practice which generally favours administration prior to skin incision. We have no data on any infant outcomes, nor on late infections (up to 30 days) in the mother; these are important gaps in the evidence that warrant further research. Antimicrobial resistance is very important but more appropriately investigated by other trial designs.

Vaginal preparation with antiseptic solution before cesarean section for preventing postoperative infections

BACKGROUND

Cesarean delivery is one of the most common surgical procedures performed by obstetricians. Infectious morbidity after cesarean delivery can have a tremendous impact on the postpartum woman's return to normal function and her ability to care for her baby. Despite the widespread use of prophylactic antibiotics, postoperative infectious morbidity still complicates cesarean deliveries. This is an update of a Cochrane Review first published in 2010 and subsequently updated in 2012, twice in 2014, in 2017 and 2018.

OBJECTIVES

To determine if cleansing the vagina with an antiseptic solution before a cesarean delivery decreases the risk of maternal infectious morbidities, including endometritis and wound complications. We also assessed the side effects of vaginal cleansing solutions to determine adverse events associated with the intervention.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth's Trials Register, ClinicalTrials.gov, the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) (7 July 2019), and reference lists of retrieved studies.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) and quasi-RCTs assessing the impact of vaginal cleansing immediately before cesarean delivery with any type of antiseptic solution versus a placebo solution/standard of care on post-cesarean infectious morbidity. Cluster-RCTs were eligible for inclusion, but we did not identify any. We excluded trials that utilized vaginal preparation during labor or that did not use antibiotic surgical prophylaxis. We also excluded any trials using a cross-over design. We included trials published in abstract form only if sufficient information was present in the abstract on methods and outcomes to analyze.

DATA COLLECTION AND ANALYSIS

At least three of the review authors independently assessed eligibility of the studies. Two review authors were assigned to extract study characteristics, quality assessments, and data from eligible studies.

MAIN RESULTS

We included 21 trials, reporting results for 7038 women evaluating the effects of vaginal cleansing (17 using povidone-iodine, 3 chlorhexidine, 1 benzalkonium chloride) on post-cesarean infectious morbidity. Trials used vaginal preparations administered by sponge sticks, douches, or soaked gauze wipes. The control groups were typically no vaginal preparation (17 trials) or the use of a saline vaginal preparation (4 trials). One trial did not report on any outcomes of interest. Trials were performed in 10 different countries (Saudi Arabia, Pakistan, Iran, Thailand, Turkey, USA, Egypt, UK, Kenya and India). The overall risk of bias was low for areas of attrition, reporting, and other bias. About half of the trials had low risk of selection bias, with most of the remainder rated as unclear. Due to lack of blinding, we rated performance bias as high risk in nearly one-third of the trials, low risk in one-third, and unclear in one-third. Vaginal preparation with antiseptic solution immediately before cesarean delivery probably reduces the incidence of post-cesarean endometritis from 7.1% in control groups to 3.1% in vaginal cleansing groups (average risk ratio (aRR) 0.41, 95% confidence interval (CI) 0.29 to 0.58; 20 trials, 6918 women; moderate-certainty evidence). This reduction in endometritis was seen for both iodine-based solutions and chlorhexidine-based solutions. Risks of postoperative fever and postoperative wound infection are also probably reduced by vaginal antiseptic preparation (fever: aRR 0.64, 0.50 to 0.82; 16 trials, 6163 women; and wound infection: RR 0.62, 95% CI 0.50 to 0.77; 18 trials, 6385 women; both moderate-certainty evidence). Two trials found that there may be a lower risk of a composite outcome of wound complication or endometritis in women receiving preoperative vaginal preparation (RR 0.46, 95% CI 0.26 to 0.82; 2 trials, 499 women; low-certainty evidence). No adverse effects were reported with either the povidone-iodine or chlorhexidine vaginal cleansing. Subgroup analysis suggested a greater effect with vaginal preparations for those women in labour versus those not in labour for four out of five outcomes examined (post-cesarean endometritis; postoperative fever; postoperative wound infection; composite wound complication or endometritis). This apparent difference needs to be investigated further in future trials. We did not observe any subgroup differences between women with ruptured membranes and women with intact membranes.

AUTHORS' CONCLUSIONS

Vaginal preparation with povidone-iodine or chlorhexidine solution compared to saline or not cleansing immediately before cesarean delivery probably reduces the risk of post-cesarean endometritis, postoperative fever, and postoperative wound infection. Subgroup analysis found that these benefits were typically present whether iodine-based or chlorhexidine-based solutions were used and when women were in labor before the cesarean. The suggested benefit in women in labor needs further investigation in future trials. There was moderate-certainty evidence using GRADE for all reported outcomes, with downgrading decisions based on limitations in study design or imprecision. As a simple intervention, providers may consider implementing preoperative vaginal cleansing with povidone-iodine or chlorhexidine before performing cesarean deliveries. Future research on this intervention being incorporated into bundles of care plans for women receiving cesarean delivery will be needed.

Using the new definition of intraamniotic infection - is there morbidity among the women left out?

Background: Recently, ACOG released updated definitions for intraamniotic infection (IAI): maternal fever (≥38.0 °C) and ≥1 symptom (fetal tachycardia, maternal white blood cell count >15,000/mm³ or purulent discharge). Treatment was no longer recommended for women with fever <39.0 °C plus maternal tachycardia or fundal tenderness (previous criteria). The objective of this study was to compare postpartum infectious morbidity among women meeting previous criteria (but not the new IAI criteria) to women meeting new IAI criteria.Methods: Retrospective cohort of women delivering vaginally at a single academic center. Demographics, antepartum and intrapartum characteristics of women who met diagnostic criteria for chorioamnionitis (previous criteria) compared to those who met IAI criteria using bivariate statistics. The primary outcome was a composite of postpartum infection, including: endometritis, perineal infection, sepsis, urinary tract infection, pyelonephritis. Backward-stepwise elimination used to estimate odds of primary outcome.Results: Of 229 women who met previous IAI criteria, 51 (22.3%) did not meet new IAI criteria. Women no longer meeting IAI criteria were younger (25 versus 27 years, p = .02), more likely to have gestational hypertension (16.0 versus 3.4%, p < .01), and less likely to have third or fourth degree lacerations (2.0 versus 13.4%, p = .02). No difference in antibiotic receipt was observed. Postpartum infection occurred in 16/229 (7.0%) women overall; five (9.8%) in those not meeting new IAI criteria, and 11 (6.2%) meeting new IAI criteria. After adjusting for confounders, there was no difference in odds of postpartum infection (aOR 1.65, 95% CI 0.55-4.99).Conclusions/implications: Among women who met old ACOG criteria for IAI, but not the new criteria, postpartum infection occurred in nearly 10%. This number could be higher if these women were not treated with antibiotics.

Vaginal preparation with antiseptic solution before cesarean section for preventing postoperative infections

BACKGROUND

Cesarean delivery is one of the most common surgical procedures performed by obstetricians. Infectious morbidity after cesarean delivery can have a tremendous impact on the postpartum woman's return to normal function and her ability to care for her baby. Despite the widespread use of prophylactic antibiotics, postoperative infectious morbidity still complicates cesarean deliveries. This is an update of a Cochrane review first published in 2010 and subsequently updated in 2012, and twice in 2014.

OBJECTIVES

To determine if cleansing the vagina with an antiseptic solution before a cesarean delivery decreases the risk of maternal infectious morbidities, including endometritis and wound complications. We also assessed the side effects of vaginal cleansing solutions to determine adverse events associated with the intervention.

SEARCH METHODS

We searched Cochrane Pregnancy and Childbirth's Trials Register, ClinicalTrials.gov, the WHO International Clinical Trials Registry Platform (ICTRP) (10 July 2017), and reference lists of retrieved studies.

SELECTION CRITERIA

We included randomized trials and one quasi-randomized trial assessing the impact of vaginal cleansing immediately before cesarean delivery with any type of antiseptic solution versus a placebo solution/standard of care on post-cesarean infectious morbidity. Cluster-randomized trials were eligible for inclusion but none were identified. We excluded trials that utilized vaginal preparation during labor or that did not use antibiotic surgical prophylaxis. We also excluded any trials using a cross-over design.

DATA COLLECTION AND ANALYSIS

At least three of the review authors independently assessed eligibility of the studies. Two review authors were assigned to extract study characteristics, quality assessments, and data from eligible studies.

MAIN RESULTS

We included 11 trials reporting results for 3403 women evaluating the effects of vaginal cleansing (eight using povidone-iodine, two chlorhexidine, one benzalkonium chloride) on post-cesarean infectious morbidity. Additionally, some trials used vaginal preparations using sponge sticks, douches, or soaked gauze wipes. The control groups were typically no vaginal preparation (eight trials) or the use of a saline vaginal preparation (three trials). The risk of bias in the studies reduced our confidence in the results for endometritis outcomes.Vaginal preparation with antiseptic solution immediately before cesarean delivery probably reduces the incidence of post-cesarean endometritis from 8.7% in control groups to 3.8% in vaginal cleansing groups (average risk ratio (RR) 0.36, 95% confidence interval (CI) 0.20 to 0.63, 10 trials, 3283 women, moderate quality of evidence). Subgroup analysis could not rule out larger reductions in endometritis with antiseptics in women who were in labor or in women whose membranes had ruptured when antiseptics were used. Risks of postoperative fever and postoperative wound infection may be slightly lowered by antiseptic preparation, but the confidence intervals around the effects for both outcomes are consistent with a large reduction in risk and no difference between groups (fever: RR 0.87 (0.72 to 1.05; wound infection: RR 0.74 (95% CI 0.49 to 1.11), both moderate-quality evidence). Two trials reported a lower risk of a composite outcome of wound complication or endometritis in women receiving preoperative vaginal preparation (RR 0.46, 95% CI 0.26 to 0.82, two trials, 499 women, moderate-quality evidence). No adverse effects were reported with either the povidone-iodine or chlorhexidine vaginal cleansing.

AUTHORS' CONCLUSIONS

Vaginal preparation with povidone-iodine or chlorhexidine solution compared to saline or not cleansing immediately before cesarean delivery probably reduces the risk of post-cesarean endometritis. Subgroup analysis could not rule out larger reductions in endometritis with antiseptics in women who were in labor or in women whose membranes had ruptured when antiseptics were used.The quality of the evidence using GRADE was moderate for all reported outcomes. We downgraded the outcome of post-cesarean endometritis and composite of wound complications or endometritis for risk of bias and postoperative fever and postoperative wound infections for wide CIs.As a simple, generally inexpensive intervention, providers may consider implementing preoperative vaginal cleansing with povidone-iodine or chlorhexidine before performing cesarean deliveries.

Vaginal preparation with antiseptic solution before cesarean section for preventing postoperative infections

BACKGROUND

Cesarean delivery is one of the most common surgical procedures performed by obstetricians. Infectious morbidity after cesarean delivery can have a tremendous impact on the postpartum woman's return to normal function and her ability to care for her baby. Despite the widespread use of prophylactic antibiotics, postoperative infectious morbidity still complicates cesarean deliveries.

OBJECTIVES

To determine if cleansing the vagina with an antiseptic solution before a cesarean delivery decreases the risk of maternal infectious morbidities, including endometritis and wound complications.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (10 December 2014).

SELECTION CRITERIA

We included randomized and quasi-randomized trials assessing the impact of vaginal cleansing immediately before cesarean delivery with any type of antiseptic solution versus a placebo solution/standard of care on post-cesarean infectious morbidity.

DATA COLLECTION AND ANALYSIS

We independently assessed eligibility and quality of the studies.

MAIN RESULTS

Seven trials randomizing 2816 women (2635 analyzed) evaluated the effects of vaginal cleansing (all with povidone-iodine) on post-cesarean infectious morbidity. The risk of bias was generally low, with the quality of most of the studies being high. Vaginal preparation immediately before cesarean delivery significantly reduced the incidence of post-cesarean endometritis from 8.3% in control groups to 4.3% in vaginal cleansing groups (average risk ratio (RR) 0.45, 95% confidence interval (CI) 0.25 to 0.81, seven trials, 2635 women). The risk reduction was particularly strong for women who were already in labor at the time of the cesarean delivery (7.4% in the vaginal cleansing group versus 13.0% in the control group; RR 0.56, 95% CI 0.34 to 0.95, three trials, 523 women) and for women with ruptured membranes (4.3% in the vaginal cleansing group versus 17.9% in the control group; RR 0.24, 95% CI 0.10 to 0.55, three trials, 272 women). No other outcomes realized statistically significant differences between the vaginal cleansing and control groups. No adverse effects were reported with the povidone-iodine vaginal cleansing.The quality of the evidence using GRADE was low for post-cesarean endometritis, moderate for postoperative fever, and low for wound infection.

AUTHORS' CONCLUSIONS

Vaginal preparation with povidone-iodine solution immediately before cesarean delivery reduces the risk of postoperative endometritis. This benefit is particularly realized for women undergoing cesarean delivery, who are already in labor or who have ruptured membranes. As a simple, generally inexpensive intervention, providers should consider implementing preoperative vaginal cleansing with povidone-iodine before performing cesarean deliveries.

Different classes of antibiotics given to women routinely for preventing infection at caesarean section

BACKGROUND

Caesarean section increases the risk of postpartum infection for women and prophylactic antibiotics have been shown to reduce the incidence; however, there are adverse effects. It is important to identify the most effective class of antibiotics to use and those with the least adverse effects.

OBJECTIVES

To determine, from the best available evidence, the balance of benefits and harms between different classes of antibiotic given prophylactically to women undergoing caesarean section.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (30 September 2014) and reference lists of retrieved papers.

SELECTION CRITERIA

We included randomised controlled trials comparing different classes of prophylactic antibiotics given to women undergoing caesarean section. We excluded trials that compared drugs with placebo or drugs within a specific class; these are assessed in other Cochrane reviews.

DATA COLLECTION AND ANALYSIS

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

MAIN RESULTS

We included 35 studies of which 31 provided data on 7697 women. For the main comparison between cephalosporins versus penicillins, there were 30 studies of which 27 provided data on 7299 women. There was a lack of good quality data and important outcomes often included only small numbers of women.For the comparison of a single cephalosporin versus a single penicillin (Comparison 1 subgroup 1), we found no significant difference between these classes of antibiotics for our chosen most important seven outcomes namely: maternal sepsis - there were no women with sepsis in the two studies involving 346 women; maternal endometritis (risk ratio (RR) 1.11, 95% confidence interval (CI) 0.81 to 1.52, nine studies, 3130 women, random effects, moderate quality of the evidence); maternal wound infection (RR 0.83, 95% CI 0.38 to 1.81, nine studies, 1497 women, random effects, low quality of the evidence), maternal urinary tract infection (RR 1.48, 95% CI 0.89 to 2.48, seven studies, 1120 women, low quality of the evidence) and maternal composite adverse effects (RR 2.02, 95% CI 0.18 to 21.96, three studies, 1902 women, very low quality of the evidence). None of the included studies looked for infant sepsis nor infant oral thrush.This meant we could only conclude that the current evidence shows no overall difference between the different classes of antibiotics in terms of reducing maternal infections after caesarean sections. However, none of the studies reported on infections diagnosed after the initial postoperative hospital stay. We were unable to assess what impact, if any, the use of different classes of antibiotics might have on bacterial resistance.

AUTHORS' CONCLUSIONS

Based on the best currently available evidence, cephalosporins and penicillins have similar efficacy at caesarean section when considering immediate postoperative infections. We have no data for outcomes on the baby, nor on late infections (up to 30 days) in the mother. Clinicians need to consider bacterial resistance and women's individual circumstances.

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.

Vaginal preparation with antiseptic solution before cesarean section for preventing postoperative infections

BACKGROUND

Cesarean delivery is one of the most common surgical procedures performed by obstetricians. Infectious morbidity after cesarean delivery can have a tremendous impact on the postpartum woman's return to normal function and her ability to care for her baby. Despite the widespread use of prophylactic antibiotics, postoperative infectious morbidity still complicates cesarean deliveries.

OBJECTIVES

To determine if cleansing the vagina with an antiseptic solution before a cesarean delivery decreases the risk of maternal infectious morbidities, including endometritis and wound complications.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (21 July 2014).

SELECTION CRITERIA

We included randomized and quasi-randomized trials assessing the impact of vaginal cleansing immediately before cesarean delivery with any type of antiseptic solution versus a placebo solution/standard of care on post-cesarean infectious morbidity.

DATA COLLECTION AND ANALYSIS

We independently assessed eligibility and quality of the studies.

MAIN RESULTS

Five trials randomizing 1946 women (1766 analyzed) evaluated the effects of vaginal cleansing (all with povidone-iodine) on post-cesarean infectious morbidity. The risk of bias was generally low, with the quality of most of the studies being high. Vaginal preparation immediately before cesarean delivery significantly reduced the incidence of post-cesarean endometritis from 7.2% in control groups to 3.6% in vaginal cleansing groups (average risk ratio (RR) 0.39, 95% confidence interval (CI) 0.16 to 0.97, five trials, 1766 women). The risk reduction was particularly strong for women with ruptured membranes (1.4% in the vaginal cleansing group versus 15.4% in the control group; RR 0.13, 95% CI 0.02 to 0.66, two trials, 148 women). No other outcomes realized statistically significant differences between the vaginal cleansing and control groups. No adverse effects were reported with the povidone-iodine vaginal cleansing.The quality of the evidence using GRADE was low for post-cesarean endometritis, moderate for postoperative fever, and low for wound infection.

AUTHORS' CONCLUSIONS

Vaginal preparation with povidone-iodine solution immediately before cesarean delivery reduces the risk of postoperative endometritis. This benefit is particularly realized for women undergoing cesarean delivery with ruptured membranes. As a simple, generally inexpensive intervention, providers should consider implementing preoperative vaginal cleansing with povidone-iodine before performing cesarean deliveries.

Vaginal preparation with antiseptic solution before cesarean section for preventing postoperative infections

BACKGROUND

Cesarean delivery is one of the most common surgical procedures performed by obstetricians. Infectious morbidity after cesarean delivery can have a tremendous impact on the postpartum woman's return to normal function and her ability to care for her baby. Despite the widespread use of prophylactic antibiotics, postoperative infectious morbidity still complicates cesarean deliveries.

OBJECTIVES

To determine if cleansing the vagina with an antiseptic solution before a cesarean delivery decreases the risk of maternal infectious morbidities, including endometritis and wound complications.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (8 August 2012).

SELECTION CRITERIA

We included randomized and quasi-randomized trials assessing the impact of vaginal cleansing immediately before cesarean delivery with any type of antiseptic solution versus a placebo solution/standard of care on post-cesarean infectious morbidity.

DATA COLLECTION AND ANALYSIS

We independently assessed eligibility and quality of the studies.

MAIN RESULTS

Five trials randomizing 1946 women (1766 analyzed) evaluated the effects of vaginal cleansing (all with povidone-iodine) on post-cesarean infectious morbidity. The risk of bias was generally low, with the quality of most of the studies being high. Vaginal preparation immediately before cesarean delivery significantly reduced the incidence of post-cesarean endometritis from 7.2% in control groups to 3.6% in vaginal cleansing groups (average risk ratio (RR) 0.39, 95% confidence interval (CI) 0.16 to 0.97, five trials, 1766 women). The risk reduction was particularly strong for women with ruptured membranes (1.4% in the vaginal cleansing group versus 15.4% in the control group; RR 0.13, 95% CI 0.02 to 0.66, two trials, 148 women). No other outcomes realized statistically significant differences between the vaginal cleansing and control groups. No adverse effects were reported with the povidone-iodine vaginal cleansing.

AUTHORS' CONCLUSIONS

Vaginal preparation with povidone-iodine solution immediately before cesarean delivery reduces the risk of postoperative endometritis. This benefit is particularly realized for women undergoing cesarean delivery with ruptured membranes. As a simple, generally inexpensive intervention, providers should consider implementing preoperative vaginal cleansing with povidone-iodine before performing cesarean deliveries.

Different classes of antibiotics given to women routinely for preventing infection at caesarean section

BACKGROUND

Caesarean section increases the risk of postpartum infection for women and prophylactic antibiotics have been shown to reduce the incidence; however, there are adverse effects. It is important to identify the most effective class of antibiotics to use and those with the least adverse effects.

OBJECTIVES

To determine, from the best available evidence, the balance of benefits and harms between different classes of antibiotic given prophylactically to women undergoing caesarean section.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (April 2010) and reference lists of retrieved papers.

SELECTION CRITERIA

We included randomised controlled trials comparing different classes of prophylactic antibiotics given to women undergoing caesarean section. We excluded trials that compared drugs with placebo or drugs within a specific class; these are assessed in other Cochrane Reviews.

DATA COLLECTION AND ANALYSIS

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

MAIN RESULTS

We included 29 studies of which 25 provided data on 6367 women. There was a lack of good quality data and important outcomes often included only small numbers of women. This meant we could only conclude that the current evidence shows no overall difference between the different classes of antibiotics in terms of reducing maternal infections after caesarean sections. However, none of the studies looked at outcomes on the baby, nor did they report infections diagnosed after the initial postoperative hospital stay. We were unable to assess what impact, if any, the use of different classes of antibiotics might have on bacterial resistance.

AUTHORS' CONCLUSIONS

Based on the best currently available evidence, cephalosporins and penicillins have similar efficacy at caesarean section when considering immediate postoperative infections. We have no data for outcomes on the baby, nor on late infections (up to 30 days) in the mother. Clinicians need to consider bacterial resistance and women's individual circumstances.

Vaginal preparation with antiseptic solution before cesarean section for preventing postoperative infections

BACKGROUND

Cesarean delivery is one of the most common surgical procedures performed by obstetricians. Infectious morbidity after cesarean delivery can have a tremendous impact on the postpartum woman's return to normal function and her ability to care for her baby. Despite the widespread use of prophylactic antibiotics, postoperative infectious morbidity still complicates cesarean deliveries.

OBJECTIVES

To determine if cleansing the vagina with an antiseptic solution before a cesarean delivery decreases the risk of maternal infectious morbidities, including endometritis and wound complications.

SEARCH STRATEGY

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

SELECTION CRITERIA

We included randomized trials assessing the impact of vaginal cleansing immediately before cesarean delivery with any type of antiseptic solution versus a placebo solution/standard of care on post-cesarean infectious morbidity.

DATA COLLECTION AND ANALYSIS

We independently assessed eligibility and quality of the studies.

MAIN RESULTS

Four trials (involving 1361 randomized and 1198 analyzed women) evaluated the effects of vaginal cleansing (all with povidone-iodine) on post-cesarean infectious morbidity. The risk of bias was generally low, with the quality of most of the studies being high. Vaginal preparation immediately before cesarean delivery significantly reduced the incidence of post-cesarean endometritis from 9.4% in control groups to 5.2% in vaginal cleansing groups (risk ratio (RR) 0.57, 95% confidence interval (CI) 0.38 to 0.87, four trials, 1198 women). The risk reduction was particularly strong for women with ruptured membranes (1.4% in the vaginal cleansing group versus 15.4% in the control group; RR 0.13, 95% CI 0.02 to 0.66, two trials, 148 women). No other outcomes realized statistically significant differences between the vaginal cleansing and control groups. No adverse effects were reported with the povidone-iodine vaginal cleansing.

AUTHORS' CONCLUSIONS

Vaginal preparation with povidone-iodine solution immediately before cesarean delivery reduces the risk of postoperative endometritis. This benefit is particularly realized for women undergoing cesarean delivery with ruptured membranes. As a simple, generally inexpensive intervention, providers should consider implementing preoperative vaginal cleansing with povidone-iodine before performing cesarean deliveries.

Vaginal cleansing before cesarean delivery to reduce postoperative infectious morbidity: a randomized, controlled trial

OBJECTIVE

The objective of the study was to determine whether vaginal preparation with povidone iodine before cesarean delivery decreased the risk of postoperative maternal morbidities.

STUDY DESIGN

The design of the study was a randomized, controlled trial in women undergoing cesarean delivery with subjects assigned to have a preoperative vaginal cleansing with povidone iodine or to a standard care group (no vaginal wash). The primary outcome was a composite of postoperative fever, endometritis, sepsis, readmission, wound infection, or complication.

RESULTS

There were 155 vaginal cleansing subjects and 145 control subjects. Overall, 9.0% developed the composite outcome, with fewer women in the cleansing group (6.5%) compared with the control group (11.7%), although the difference was not statistically significant (relative risk, 0.55; 95% confidence interval, 0.26-1.11; P = .11). Length of surgery, being in labor, and having a dilated cervix were all associated with the composite morbidity outcome.

CONCLUSION

Vaginal cleansing with povidone iodine before cesarean delivery may decrease postoperative morbidities, although the reduction is not statistically significant.

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.

Impact of interconception antibiotics on the endometrial microbial flora

OBJECTIVE

The purpose of this study was to evaluate the impact of an interconception antibiotic regimen on endometrial microbial flora and histologic type.

STUDY DESIGN

This was a secondary analysis of a double-blind randomized placebo-controlled trial of prophylactic metronidazole plus azithromycin that was given to 241 women (antibiotics, 118 women; placebo, 123 women) with a previous preterm delivery to prevent recurrent preterm delivery. Endometrial cultures and histologic types were obtained at randomization and 2 weeks after treatment. The prevalence of either the new acquisition or the resolution of individual microbes, categories of microbes, and plasma cell endometritis were compared by chi-square or Fishers' exact tests.

RESULTS

Overall, antibiotics were associated with lower acquisition and higher resolution of microbes. Of women without Gardnerella at baseline, 14% of the women who received antibiotics vs 34% of the women who received placebo had positive endometrial culture for the organism after treatment (P < .05); of those women with G. vaginalis at baseline, 57% of the women who received antibiotics vs 33% of the women who received placebo (P < .05) had a negative follow-up culture. Other gram-negative rods, especially aerobes in general, manifested similar patterns. The impact on anaerobes and plasma cell endometritis was not definitive, but there was a trend toward the increased resolution of the former (77% vs 55%) and reduced acquisition of the latter (28% vs 50%).

CONCLUSION

The antibiotic regimen prevented the acquisition and promoted the resolution, but not the eradication, of gram-negative rods such as G. vaginalis and the aerobic subcategory.

Probiotic alternatives to reduce gastrointestinal infections: the poultry experience

The intestinal mucosa represents the most active defense barrier against the continuous challenge of food antigens and pathogenic microorganisms present in the intestinal lumen. Protection against harmful agents is conferred by factors such as gastric acid, peristalsis, mucus, intestinal proteolysis, and the intestinal biota. The establishment of beneficial bacterial communities and metabolites from these complex ecosystems has varying consequences for host health. This hypothesis has led to the introduction of novel therapeutic interventions based on the consumption of beneficial bacterial cultures. Mechanisms by which probiotic bacteria affect the microecology of the gastrointestinal tract are not well understood, but at least three mechanisms of action have been proposed: production/presence of antibacterial substances (e.g., bacteriocins or colicins), modulation of immune responses and specific competition for adhesion receptors to intestinal epithelium. The rapid establishment of bacterial communities has been thought to be essential for the prevention of colonization by pathogenic bacteria. Some animal models suggest that the reduction in bacterial translocation in neonatal animals could be associated with an increase in intestinal bacterial communities and bacteriocin-like inhibitory substances produced by these species. This review emphasizes the role of the intestinal microbiota in the reduction of the gastrointestinal infections and draws heavily on studies in poultry.

Prevention of neonatal group B streptococcal disease: progress, challenges and dilemmas

Significant advances in the prevention of neonatal group B streptococcal (GBS) disease have occurred in the last decade. In Australia, as well as in centres overseas, intrapartum penicillin given to carrier mothers has been shown to unequivocally decrease early onset neonatal GBS sepsis. In choosing which women should receive intrapartum chemoprophylaxis, recent data suggest that screening programmes for the detection of GBS carriage may be more effective than risk-based strategies to prevent early onset neonatal GBS sepsis. Combined vaginal and rectal swabs, collected between 35 and 37 weeks gestation, either by a health care worker or by the patient herself and inoculated onto selective media after enrichment provide the optimum conditions to detect carriage. Increasingly erythromycin and clindamycin resistance is being described overseas, which may influence the choice of antibiotics used in those allergic to penicillin. Widespread antibiotic use, particularly with broad-spectrum agents, may lead to increasing neonatal sepsis with ampicillin resistant organisms. Whilst rates of non-GBS neonatal sepsis are generally stable there is evidence suggesting that Escherichia coli sepsis in premature infants is increasing. Novel vaccination strategies for GBS are being developed that may ultimately provide broader protection for mothers and babies and eliminate the need for intrapartum antibiotics.

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 use in pregnancy and drug-resistant infant sepsis

OBJECTIVE

We sought to evaluate the effect of antepartum and intrapartum antibiotic use on antimicrobial-resistant neonatal sepsis.

STUDY DESIGN

We analyzed perinatal outcomes for 8474 pregnancies (8593 live births) delivered at 6 hospitals. Data were collected regarding maternal antibiotic use and perinatal course, neonatal cultures, and outcomes. The diagnosis of confirmed neonatal sepsis required at least one positive blood or cerebrospinal fluid culture. Neonatal cultures were evaluated on the basis of the occurrence and timing of maternal antibiotic exposure.

RESULTS

There were 96 neonates with confirmed sepsis (11.2/1000 live births). Sepsis was 19.3-fold more common after preterm birth (57 vs 3. 1/1000; P <.001), with 76% of septic infants being delivered preterm. Forty-five percent of pathogens were ampicillin resistant. Ampicillin resistance increased with preterm birth (50% vs 26%; P =. 04), antepartum antibiotics (57% vs 34%; P =.03), intrapartum antibiotics (55% vs 28%; P <.01), and any prenatal antibiotic exposure (52% vs 22%; P =.01). Infection with an organism resistant to at least one maternal antibiotic was more common with intrapartum antibiotic exposure than with antepartum exposure only (57% vs 17%; P =.01). Regarding early-onset sepsis (n = 55), ampicillin resistance was more common with intrapartum antibiotics (50% vs 16%; P <.01), and resistance to at least one maternally administered antibiotic was more frequent with intrapartum exposure (56.7% vs 0%; P <.01).

CONCLUSIONS

Maternal antibiotic treatment is associated with neonatal sepsis by organisms resistant to ampicillin and to maternally administered antibiotics.

Processing of semen in an antibiotic-rich culture medium to minimize microbial presence during in vitro fertilization

OBJECTIVE

To identify and determine the prevalence of microorganisms in preprocessed and postprocessed semen in an IVF-ET program.

DESIGN

Prospective study.

SETTING

University Teaching Hospital.

PATIENT(S)

Seventy-four men undergoing preprogram evaluation, each producing two semen samples.

INTERVENTION(S)

Semen processing with a wash and swim-up technique in a penicillin- and streptomycin-rich medium.

MAIN OUTCOME MEASURE(S)

The identity and prevalence of seminal microorganisms before and after processing.

RESULT(S)

Sixty-three percent of individual unprocessed semen samples grew microorganisms, the majority of which were nonpathogenic. Thirty-three men (44.6%) had microbes identified in repeat samples, four had identical organisms each time. Twenty (27%) had positive cultures in one sample, negative in the other. Twenty-one (28.4%) had consistently sterile semen. After seminal processing, the recovery rate for microbes was 5%. Microbial presence after processing did not correlate with either the sperm swim-up concentration or the initial microbial concentration.

CONCLUSION(S)

Bacteriospermia is common. The microorganisms found rarely are replicated and most likely represent contamination. Wash and swim-up semen preparation in an antibiotic rich culture medium effectively eliminates 95% of organisms.

Microbial flora in semen during in vitro fertilization

Semen samples from 183 consecutive unselected men participating in an in vitro fertilization program were retrospectively studied to determine the bacterial and fungal contamination rate before and after antibiotic treatment. To ascertain the influence of semen preparation (wash and swim-up method) on the incidence of microorganisms, semen from 102 male patients was studied before and after swimup. Antimicrobial treatment by prescription of antibiotics decreased the incidence of pathogens by 16.3% (P less than 0.0001). Semen processing was more effective by ridding 57.4% of semen samples of microbial contaminants (P less than 0.0001). When infection of culture media was observed during routine microscopy, all infected oocytes were degenerated, without evidence of fertilization or pronuclei.

Choice of antibiotic in nonelective cesarean section

The use of antibiotics for prophylaxis against infection among women undergoing nonelective cesarean section has become the standard of care in the United States. Many different antibiotics have been used successfully. Single-dose regimens administered after the cord is clamped have proven just as effective as multiple-dose regimens. Although the most frequently used class of antibiotics is the cephalosporin family, the single best agent has not been determined. This study was a double-blind, randomized trial in which we compared a narrow-spectrum cephalosporin (cefazolin; n = 63) with an expanded-spectrum cephamycin (cefoxitin; n = 66) and with a broad-spectrum cephalosporin (cefotaxime; n = 60) used as a single-dose prophylaxis in patients undergoing a nonelective cesarean section. Of the 194 patients enrolled in the study, 189 were evaluable. There was no significant difference between the groups in mean age, gravidity, parity, duration of labor, duration of ruptured membranes, number of vaginal examinations, or socioeconomic status (socioeconomic status was defined by third-party coverage). There was no significant difference among the antibiotics in the incidence of immediate or delayed postoperative infections. These data indicate that a less expensive, narrow-spectrum cephalosporin is as effective as more expensive, broader-spectrum cephamycins and cephalosporins as prophylaxis for patients undergoing nonelective cesarean section.

Treatment of postpartum endometritis

In this study, cefoxitin alone (2 gm, every 8 hours) was generally sufficient to cure postpartum endometritis, even when the patient had received prophylaxis with a beta-lactam antibiotic. When single-agent therapy fails, addition of ampicillin usually results in a prompt clinical response.

Antibiotic prophylaxis: is there a difference?

Seven antibiotics, administered in 10 different regimens for prophylaxis, were randomly assigned to 1580 patients who were delivered by cesarean section. Cefazolin 1 gm, administered for three doses, served as the control group. Cefazolin 1 gm, cefazolin 2 gm, cefoxitin 1 gm, cefoxitin 2 gm, cefonicid 1 gm, cefotetan 1 gm, ceftizoxime 1 gm, ampicillin 2 gm, and piperacillin 4 gm were all administered in a single dose. Four antibiotics proved to be superior in preventing postpartum endometritis: ampicillin 2 gm (p = 0.03), cefazolin 2 gm (p = 0.005), piperacillin 4 gm (p = 0.0007), and cefotetan 1 gm (p = 0.0001). Single-dose cephalosporin antibiotic prophylaxis was found to result in approximately a twofold increase in Enterococcus faecalis colonization of the vagina (p less than 0.01). This may be significant in patients in whom postpartum endometritis develops and who have failure of initial treatment with a broad-spectrum cephalosporin, e.g., cefoxitin or cefotetan, or a combination such as clindamycin or metronidazole plus an aminoglycoside. Rupture of amniotic membranes for a half hour or more was associated with an increased risk for postpartum endometritis. The use of internal fetal monitoring was associated with an increased risk of soft tissue pelvic infection.

Perspectives on the bacteriology of postoperative obstetric-gynecologic infections

The development of postoperative infections is influenced by both host and external factors. The present report focuses on the influence of prophylactic agents on the apparent cause of infection after cesarean section and vaginal hysterectomy. The correlation between in vitro susceptibility patterns of potential pathogens and normal flora and in vivo response is also considered.

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.

Cesarean section prophylaxis: comparison of two doses with three doses of mezlocillin

A prospective randomized double-blind comparison of two doses, with three doses of mezlocillin for nonelective cesarean section prophylaxis was performed. One hundred seven (107) patients were evaluated. Mezlocillin (4 g) was given post-cord clamping and then at 4-h intervals for a total of two doses or three doses. The incidence of febrile morbidity was lower in the three-dose group (2 of 46, 4%) than the two-dose group (14 of 61, 23%) (P less than 0.02). However, the incidence of infectious morbidity was not different between the three-dose group (3 of 46, 7%) and the two-dose group (10 of 61, 16%), and the incidence of endomyometritis was similar in the two groups (6.5% vs 9.8%). Among failures of prophylaxis there were no differences compared to successes in the number of potential commensals or potential pathogens cultured from amniotic fluid. However, the proportion of failures among patients with both commensals and potential pathogens isolated (10/58) was significantly greater than among patients with none or only commensals isolated (1/37) (P less than 0.03). We found mezlocillin to be an effective agent for perioperative cesarean section prophylaxis with two doses as effective as three doses. The presence of clinically important organisms in the amniotic fluid at the time of operation typified patients with postoperative infectious complications despite perioperative prophylaxis.

Risk factors for postcesarean endomyometritis

Postcesarean endomyometritis is the most common nosocomial infection treated by obstetrician-gynecologists. One important prevention strategy is the use of perioperative antibiotic prophylaxis initiated after occlusion of the umbilical cord for parturient patients with a high risk of this infection. However, the identification of these high risk patients remains problematic. Numerous clinical risk factors have been identified in the literature. Important intrinsic risk factors include indigent socioeconomic status, anemia, and preterm gestational age at the time of cesarean section. The three most consistently identified extrinsic risk factors include labor prior to cesarean section, the duration of ruptured chorioamniotic membranes, and the number of preoperative vaginal examinations. Alternatively, many investigators have attempted to define high-risk patients utilizing various laboratory tests, such as Gram staining or bacterial culture of amniotic fluid, chorioamniotic membranes, or endometrial biopsy specimens; although specific, these tests have not been sufficiently sensitive predictors of infection. Currently, assessment of the duration of ruptured membranes and length of labor remain the most sensitive, readily available, and therefore clinically useful predictors of postcesarean endomyometritis.

Patient cost in the treatment of postsurgical female pelvic infection

Soft tissue female pelvic infections, that is, postpartum endomyometritis, pelvic cellulitis, and salpingitis, are frequently polymicrobial, involving aerobic and anaerobic bacteria. The most common antibiotic regimen employed for the treatment of these patients is clindamycin and an aminoglycoside. Single-agent therapy, utilizing the newer beta-lactams, is more economical, potentially less toxic, and as effective.