Effect of anesthesia on the success rate of external cephalic version: GRADE- assessed systematic review and meta-analysis of randomized controlled trials.

Background: External cephalic version (ECV) is a medical procedure in which an extracorporeal manipulation is performed to render the breech presentation (BP) fetus in the cephalic position. The use of anesthesia to facilitate repositioning has been evaluated in various randomized clinical trials (RCTs), but its potential effectiveness remains controversial.

Methods: A systematic literature search was carried out in 8 electronic databases. In the meta-analysis, a random effects model was used to calculate the pooled relative risk (RR) and its 95% confidence interval (CI), and the pooled standardized mean difference (SMD) and its 95% CI, in order to systematically assess the effect of anesthesia on the success rates of ECV, vaginal delivery, cesarean delivery as well as other outcomes. Relevant subgroup analyses, publication bias test and sensitivity analyses were also conducted.

Results: This review included 17 RCTs. Women who received anesthesia had a significantly higher incidence of successful ECV (RR: 1.37, 95% CIs: 1.19-1.58) and vaginal delivery (RR: 1.23, 95% CIs: 1.03-1.47), and a significantly lower incidence of cesarean delivery (RR: 0.69, 95% CIs: 0.53-0.91), compared with those who did not.

Conclusion: The administration of anesthesia not only significantly reduces maternal pain but also significantly increases the success rate of ECV in women with malpresentation at term, leading to a significant rise in the incidence of vaginal delivery. However, it may increase the incidence of maternal hypotension.

Systematic review registration: The protocol was prospectively registered with PROSPERO, registration CRD42022381552.