Systematic review of the effectiveness of remifentanil in term breech pregnancies undergoing external cephalic...

External cephalic version (ECV) is a moderately painful procedure used to turn a fetus from a non-vertex to cephalic position. This systematic review and meta-analysis compared intravenous remifentanil with other analgesia or no analgesia or placebo on the success rate and associated pain of ECV.

Systematic searches for randomised controlled trials using remifentanil during ECV for non-cephalic term singleton pregnancies were conducted in EMBASE, MEDLINE and the Cochrane Library to October 2021. The primary outcomes were successful ECV and maternal pain; secondary outcomes included mode of delivery and adverse effects. The Cochrane Risk of Bias tool was used and meta-analysis undertaken if there were ≥2 comparable studies.

Four trials were identified, three placebo-controlled and one vs no analgesia, totalling 482 participants. Comparisons against nitrous oxide or neuraxial anaesthesia were not analysed. Two studies had a low overall risk of bias, and two had some concern for bias. Remifentanil compared with placebo increased the success of ECV by 43% (risk ratio [RR] 1.43; 95% confidence interval [CI] 1.14 to 1.78). Pain scores (0-10) were lower (mean difference -1.97; 95% CI -2.49 to -1.46) whilst there was no impact on caesarean delivery rate (RR 0.97; 95% CI 0.81 to 1.17). Adverse events were rare, with fetal bradycardia observed less often with remifentanil than placebo.

Remifentanil increases the procedural success of ECV and reduces pain compared with placebo. Trials were at low risk of bias and contained a sufficient number of participants to have reasonable confidence in this finding.