Comparing different types of antibiotics given routinely to women at caesarean section to prevent infections

Background

Women undergoing caesarean section have an increased likelihood of infection compared with women who give birth vaginally. These infections can be in the urine, surgical incision, or the lining of the womb (endometritis). The infections can become serious, causing, for example, an abscess in the pelvis or infection in the blood, and very occasionally can lead to the mother's death. Sound surgical techniques are important for reducing infections, along with skin antiseptics and antibiotics. However, antibiotics can cause adverse effects such as nausea, vomiting, skin rash and rarely allergic reactions in the mother, and the risk of thrush (candida) for the mother and the baby. Antibiotics, given to women around the time of giving birth, can also change the baby's gut flora and thus may interfere with the baby's developing immune system.

Our review question

We asked if cephalosporin antibiotics were better than penicillins for women having a caesarean section. We also looked to see how other groups of antibiotics compared.

What we found

When comparing cephalosporins against penicillins, we found 27 studies, involving 7299 women as of September 2014. The quality of the studies was generally unclear and three studies reported drug company funding. Cephalosporins and penicillins had similar effects in reducing infections after caesareans and similar adverse effects. However, none of the studies considered infections after the women left hospital. None of the studies looked at outcomes on the babies. Other evidence show tetracyclines can cause discolouration of teeth in children and are best avoided. Consideration also needs to be given to antibiotics compatible with breastfeeding. We were unable to assess bacterial resistance, and this is crucial when considering which antibiotic might be used.

What our results mean

At caesarean sections, cephalosporins and penicillins have similar benefits and side effects for mothers when considering infections immediately following the operation but there is no information on babies. Clinicians need to consider bacterial resistance and women's individual circumstances.

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.

Read the full abstract...
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 (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.

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