The experience is considered crucial in medicine in general, and in obstetrics particularly. Super-specialization in medicine improves the experience acquisition and makes the daily work safer. It seems logical that the introduction of a super-specialized team in ECV, would improve the success rate and would make the procedure safer. National and International Obstetrics organizations should not only support but also lead specific formation and accreditation plans for External Cephalic Version specialization for obstetricians, midwives, and anesthesiologists in light of this and previous results.
In this study, the success rate of ECV increases from 47.2% (95% CI 31.7–63.2) to 74.0% (66.6–80.5%) with the introduction of a dedicated team. The number needed to treat was 6.7, meaning that 6.7 ECVs performed by the experienced dedicated ECV team led to one additional vaginal delivery in comparison with ECVs performed by the non-dedicated team. The creation of a dedicated experienced team of obstetricians to perform ECV led to an increase in the success rate and a significant decrease in the cesarean section rate overall.
If the results are compared in nulliparas, a greater increase is reported from 38.5% (95% CI 21.8–57.6) in group B to 69.1% (95% CI 59.4–77.6).
It is a known fact that analgesia [8, 12–14, 16, 20, 23] and tocolysis [8, 11] improve the ECV success rate. The present study had remarkable procedure characteristics such as, as far as we are concerned, it is the first group in which propofol is used for deep sedation in ECV, and what tocolysis concerned, ritodrine is administered for 30 minutes just before the procedure [21, 22].
Although several prediction models for the success of ECV have been developed, none of them included the experience of the operator as a potential predictor for success[24, 25]. Kim et al. underlined the potential importance of operator experience by developing a learning curve for ECV. To achieve an expected success rate of 50% in nulliparas, approximately 57 ECV attempts are needed, and for a 70% success rate, approximately 130 attempts are needed. In multiparas, only eight to 10 cases would be necessary for an expected success rate of 50% and 70%, respectively .
Several studies have analyzed their results in ECV when it is performed by a dedicated team: single-operator[17, 18] or dedicated team[5, 10, 19, 27]. Bogner et al. showed that the ECV success rate depended not only on parity and gestational age but also on performing physician .
It should be highlighted that the success rate of ECV in this study continued to increase in the years after the introduction of the dedicated team, without a change in team members. It may indicate the development of a learning curve.
Other studies have focused on the effect of a dedicated team[10, 27]. Hickland et al. replaced their ECV obstetrician with a weekly breech clinic every 15 days and showed an increase in the success rate of ECV from 32.6–41.9% over 3 years . Thissen et al. compared ECV performed by a non-experienced team with their results after the introduction of a dedicated team. They reported an increase in the ECV success rate (39.8–59.66%) with the greatest increase in nulliparas.
Previous studies have tried to elucidate fetal and maternal factors that can predict the ECV result [6, 24, 25, 29, 30]. Normal or high amniotic fluid volume, multiparity, BMI < 35 Kg/m2, reduced bladder volume, fetal transverse lie, and increased estimated fetal weight are predictive of the success of ECV in several studies[9, 25, 29]. The present study found that normal to high amniotic fluid volume, multiparity, and lower BMI was associated with the success of ECV.
ECV is considered to be a safe procedure for achieving a cephalic presentation. Two studies analyzed ECV complications rate in dedicated team[31, 32]. Beuckens et al. reported 47.2% of ECV success and 2.63% of complications during the 48 hours next to the procedure. Rodgers et al. reported a success rate of 35% for nulliparas and 62% for multiparas and an ECV complication rate of 4.73%. In both studies, ECV was performed without analgesia nor tocolysis. The present study found that an experienced dedicated team decreases ECV complications rate from 22.2% (95% CI 11.1–37.6) to 9.3% (95% CI 5.5–14.8) with the introduction of ECV dedicated team.
Super-specialization in obstetrics is essential for improving results and maintaining safety in procedures. ECV is an effective procedure for reducing the cesarean section rate and offering a chance for a vaginal delivery. When ECV is performed by experienced obstetricians a reduction in complications rate and an increase in success rate are observed. Although how experience influences in ECV have already been analyzed, experienced dedicated team was compared with residents or non-experienced obstetricians. This study has compared the results, in terms of effectiveness and safety, between the dedicated team and experienced senior obstetricians.
The introduction of a dedicated team not only supposes an advantage in comparison with residents or other colleges but also with other experienced obstetricians. Super-specialization in ECV, in the light of this study, should be enhanced by nationals and internationals obstetrics and gynecology associations.
Some key questions still unanswered, such as, the learning curve needed, the type of anesthetic technique, the type of tocolytic drug, etc. Besides, clinical trials are needed to evaluate definitively the effectiveness of super-specialization in ECV. without the potential bias that could affect observational studies.
Strengths and Limitations
A strength of this study is the fact that it is the first prospective cohort study to assess the influence of an experienced dedicated team on the success rate of ECV in comparison with senior experienced obstetricians. This is the first study in which propofol is used for sedation in patients who underwent ECV. It should be also highlighted that in the present study ritodrine is administered for 30 minutes just before the procedure. There were no significant differences in patient and obstetric characteristics making selection bias less likely.
This study has some limitations. First, the number of women who underwent ECV in a non-dedicated team is small, which may affect the power of statistical analysis. However, differences observed in the present study, despite the lack of power, are consistent. Due to the differences in complications rate, it should be not ethical to increase patients recruited in a non-dedicated team in this study. Besides, the learning curve cannot be evaluated in this study due to the absence of temporal analysis.