Experiences with High Success Rate of External Cephalic Version and Comparisons of Different Tocolysis for Risk-effective version based on a bayesian network meta-analysis

Abstract

Background: External cephalic version (ECV) has been proved effectively in reducing the cesarean section rates, but the success rates of the procedure are uneven. Experiences of ECV with high success rate were concluded in this paper. And in order to evaluate the efficiency of the applied tocolytic agents, a corresponding bayesian-network meta-analysis was conducted.Methods: Through retrospective analysis of eighty-four single pregnant women with breech presentation near or at term who received ECV from Dalian Maternal and Child Health Care Hospital from April 2017 to November 2019, influence factors associated with the success rate of ECV were analyzed. Meanwhile, a bayesian-network meta-analysis including sixteen eligible randomized controlled trials (RCTs) about comparisons of five common tololytic agents and placebo with 3468 participants searched from Pubmed, Cochrane library and Embase databases until May 20, 2019 was conducted to identify the efficiency of ritodrine and terbutaline applied in the authors’ procedures. Results: The ECV procedures were conducted by a skilled obstetrician through strict selection of the candidates. Oral ritodrine, intravenous terbutaline in combination with epidual analgesia were applied as interventions. Success rate of ECV reached 90.48% (76/84) and the overall vaginal delivery rate is up to 88.16% (67/76). Only one patient reverted to breech presentation due to loose of the bellyband. Among the possible variables, amniotic fluid index were identified to have significantly relationship with the success rate of ECV. As the bayesian network meta-analysis proved: terbutaline, salbutamol and ritodrine played more important roles than nitroglycerine and nifedipine on the success rate of ECV. But salbutamol was found to have more common side effects than terbutaline and ritodrine.Conclusions: We conclude that factors influencing the success rate of ECV mainly include: 1. characteristics of the mothers and fetuses, 2. interventions, 3. skills of the surgeon. During ECV process, selection of patients with enough amniotic fluid and proper stature with no contraindications is essential. And a more detailed scoring standard according to the possible influence indicators of the mothers and fetuses for the feasibility of ECV should be set up in the future. Besides, application of terbutaline and ritodrine as tocolytic agents during ECV procedure were considered to be effective for increasing successful versions.