Objective: The main objective is to compare ECV results when the procedure is performed by an experienced dedicated team or by seniors obstetricians. Design: Prospective longitudinal study. Setting: Prospective analysis of ECV performed in ‘Virgen de la Arrixaca’ University Hospital between 10/1st/2018 and 12/31st/ 2019. Population or Sample: All the patients who undergo ECV in this hospital. Methods: From 10/1st/2018 to 09/31st/2019, ECV were performed by two senior experienced obstetricians who composed the dedicated team for ECV, designed as Group A. From 10/1st/ 2019 to 12/31st/ 2019, ECV was performed by two seniors obstetricians, designed as Group B. Ritodrine was administered during 30 minutes just before the procedure. Propofol was used for sedation. Main Outcome Measures: ECV Success rate, complications rate, and Vaginal delivery rate after ECV. Results: 122 pregnant women underwent an ECV attempt. 90 (73.8%) were performed by Group A and 32 (26.2%) were carried out by Group B. The ECV success rate increased from 56.3% (B) to 67.8% (A) (P=0.241). The greatest increase in the success rate was seen in nulliparous (from 39.1% to 63.5%, P=0.043). Amniotic fluid pocket (OR=1.32; P=0.035) was associated with ECV success. The complications rate decreased from 18.8% (B) to 6.7% (A) (P=0.049). Conclusions: The introduction of an experienced dedicated team reduces ECV complications rate and, in nulliparous it improves the ECV success rate. Multiparity and normal or high amniotic fluid volume increase in the ECV success rate. Funding: The authors received no funding for this work. Keywords: External Cephalic Version, Super-specialization, Breech

Objective: Compare the effectiveness and safety of the ECV when the procedure is performed by senior experienced obstetricians or by super-specialized professionals who composed a dedicated team. Design: Longitudinal prospective analysis. Setting: 1st of January of 2018 and 31st of December of 2019. Population: Pregnant women with non-cephalic presentation and no contraindication for vaginal delivery. Methods: Longitudinal prospective analysis of ECV performed in a tertiary hospital. From 1/1st/2018 to 10/1st/2019, ECV were performed by two senior experienced obstetricians who composed the dedicated team for ECV, designed as Group A. From 10/1st/2019 to 12/31st/2019, ECV was performed by two seniors obstetricians, designed as Group B. Ritodrine was administered during 30 minutes just before the procedure. Propofol was used for sedation. Main Outcome Measures: ECV success rate, ECV complication rate, cesarean section 24 h after ECV. Results: 186 pregnant women were recruited (150 patients in group A and 36 patients in group B). ECV success rate increased from 47.2% (31.7-63.2) in Group B to 74.0% (66.6-80.5) in Group A. The greatest increase in the success rate of ECV was seen in nulliparae, from 38.5% (21.8-57.6) in group B to 69.1% (59.4-77.6). Complications rate decreased from 22.2% (11.1-37.6) in Group B to 9.3% (5.5-14.8) in Group A. Conclusions: The introduction of an experienced dedicated team improves ECV success rate, especially in primiparas, and it also reduces ECV complications rate. Funding: The authors received no financial support for the research, authorship, and/or publication of this article. Keywords: Sedation, Experience, ECV, Breech presentation