Abstract: Of the 370 records that we identified as a result of the search (excluding duplicates), we regarded six abstracts and titles as potentially relevant studies. Of these six studies, three met the inclusion criteria involving 708 participants; most trials were at moderate or high risk of bias (risk mainly due to lack of blinding and high rate of incomplete data). We did not identify any ongoing trials. Although all included studies had been published in peer-reviewed journals at the time of the search and data extraction, numerical data regarding the outcome measured in one trial involving 77 participants were insufficient for inclusion in a meta-analyses. The difference in the rates of prolonged vaginal discharge or presumed cervicitis (one study; 348 participants; risk ratio (RR), 1.29; 95% confidence interval (CI) 0.72 to 2.31; low-quality evidence) and severe vaginal bleeding (two studies; 638 participants; RR 1.21; 95% CI 0.52 to 2.82; very low-quality evidence) among the two comparison groups did not reach the level for clinically important effect. In addition, there was no difference in adverse events related to antibiotics i.e. nausea/vomiting, diarrhoea, and headache among the two comparison groups (two studies; 638 participants; RR 1.69; 95% CI 0.85 to 3.34; very low-quality evidence). There were no differences in the incidence of fever (RR, 2.23; 95% CI 0.20 to 24.36), lower abdominal pain (RR, 1.03; 95% CI 0.61 to 1.72), unscheduled medical consultation (RR 2.68, 95% CI 0.97 to 7.41), and additional self-medication (RR 1.22; 95% CI 0.56 to 2.67) between the two comparison groups (one study; 290 participants; low to very low-quality evidence). As only limited data are available from three trials with overall moderate to high risk of bias, there is insufficient evidence to support use of antibiotics to reduce infectious complications following excision of the cervical transformation zone. In addition, there were minimal data about antibiotic-related adverse events and no information on the risk of developing antibiotic resistance. Antibiotics given for infection prevention after excision of the cervical transformation zone should only be used in the context of clinical research, to avoid unnecessary prescription of antibiotics and to prevent further increases in antibiotic resistance.

Plain-language summary: We searched the literature to May 2016 and found three published randomised trials that met the review inclusion criteria. We did not identify any ongoing trials. The three included studies involved 708 participants who had undergone excisional treatment to the cervix (known as laser or large loop excision of transformation zone (LLETZ) or loop electrosurgical excision procedure (LEEP)). Two studies tested a antimicrobial vaginal pessary versus no treatment; the other tested oral antibiotics compared with placebo. We found that there was no benefit to prophylactic antibiotics after LLETZ to reduce or prevent prolonged vaginal discharge, severe vaginal bleeding, fever, lower abdominal pain, unscheduled medical consultation, and additional self-medication. There was little information on antibiotic-related adverse effects. The limited evidence available does not support routinely giving antibiotics for infection prevention after LLETZ. As there are growing concerns with antibiotic resistance, antibiotics for infection prevention after excision of the cervical transformation zones should only be used in the context of clinical trials. The quality of the evidence regarding prophylactic antibiotics for preventing severe vaginal bleeding, fever, and adverse events was very low, with evidence from other comparisons being of low quality.