**12. ECV: The right moment for its performance**

The external version should be performed as of the 37th week (at term). The reasons for this recommendation are the following: the fetus is mature and, in case any problem takes place, the labour can be induced easily. Moreover, the spontaneous cephalic versions without

Even though some projects reveal that the higher amniotic fluid volume is, the more successful ECV can be. This statement has not been proved yet and it can also imply a

Pregnant women should be informed that approximately 50% of those external versions performed by an experienced professional are successful, even though the results must be

The procedures that have proved their usefulness in randomized studies are only the

In a 2005 *Cochrane*'s review, tocolytics were related to a reduction of the failure risk in external cephalic version both with nulliparous and multiparous women, as well as to a reduction in the caesarean rate. In the "tocolytic groups" the achievement of the external cephalic version in a minute and the fetal bradycardia was less common. These results are valid for tocolytics such as ritodrine, salbutamol and terbutaline (both by an intravenous or subcutaneous injection). However, no evidence has been proved in order to use other tocolytics suggested in other projects (such as the intravenous nitroglycerin, sublingual glyceryl trinitrate or nifidipine). Thus, pregnant women should be warned about the

In the same revision it was concluded that despite the fact that many multiple studies have been carried out, there is not enough scientific evidence proving the use of epidural analgesia, vibroacoustic stimulation or amnioinfusion in order to facilitate the version.

A small prospective study published in 2010 concluded that the factors increasing the probability of success and reducing the rate of adverse effects in ECV are a single attempt at the maneuver, total duration of the maneuver of less than 5minutes, and use of salbutamol

There were contradictory results regarding the outcomes using the epidural or spinal analgesia to facilitate the version maneuvers. Therefore, the use of regional analgesia in

In the case of the acoustic stimulation of the fetus, there is a small project which proved a significant reduction in the external cephalic version failure rate in midline fetal spine positions. Nevertheless, as this project is small, the confirmation of the results by other

No randomized clinical studies on the amnioinfusion practices as a method to facilitate the

The external version should be performed as of the 37th week (at term). The reasons for this recommendation are the following: the fetus is mature and, in case any problem takes place, the labour can be induced easily. Moreover, the spontaneous cephalic versions without

separately identified for each patient (level of recommendation B) (RCOG, 2006).

tocolytics adverse effects (evidence level Ia and recommendation level A).

order to facilitate the external cephalic version cannot be recommended.

projects is necessary before including this procedure into the clinical practice.

**12. ECV: The right moment for its performance** 

higher number of spontaneous revisions.

as a uterine relaxant (Delgado et al, 2010).

external version were found.

tocolytics aiming at relaxing the uterus at the version.

**11. Making the ECV easier** 

trying the external cephalic version or the reversion after a successful external cephalic version are less common at term.

The *Cochrane*'s meta-analysis on cephalic versions in fetus at term (at least 37 weeks) evidently prove that the possibility of breech presentation and the caesarean practice can be substantially reduced without significantly increasing the perinatal mortality. As a result, there are many reasons for the clinical use of the external cephalic version at term (with the suitable precautions) in any pregnant woman where the cephalic vaginal delivery probability overcomes the version risk.

However, another *Cochrane*'s meta-analysis in pregnancies at term indicated that the early external cephalic version (from the 32nd to the 37th week) has not proved any significant effect on the position of the fetus at term (from the 38th to the 40th week) or on the caesareans incidence or perinatal results. In view of the absence of evidence on the effectiveness of the early external cephalic version and the existence of (observational) studies which relate it to higher risks, no procedure can be currently recommended.

Controlled and randomized studies have established that external cephalic version at term increases the probability of cephalic presentation at delivery and that, therefore, the necessity of a caesarian is reduced. However, the success rates are low (particularly in North America and Europe). The ECV studies at term carried out in Africa expressed high success rates. However, these results were not repeated in the studies from North America and Europe. It was suggested that this situation could be caused by the pelvic structure differences in white women, making the fetus prematurely engage and, thus, hampering the ECV.

In order to solve this problem and with the purpose of increasing the success rates, the University of Toronto carried out a pilot study to determinate if the ECV at preterm (at th 34th or 35th week) could be more effective than when started at term (≥ the 37th-38th week). This study was aimed at reducing the breech presentation rates at delivery if the procedure was previously performed. If the breech presentation rate was finally reduced, an wider study to consider the caesarean rates, fetal results and neonatal adverse results should be carried out. It was observed an significant reduction both in the cephalic presentation rates at delivery (9,5%) and in the caesareans (7%). However, these results were not relevant enough since the sample was very small. No differences in the neonatal results from both groups were shown. Apart from that, the reversion rate in breech presentation was low in both groups. Besides, most of women stated that they could consider the ECV in prospective pregnancies. That shows an increase of the acceptance level (Hutton et al, 2003). at adverse

> These results show that the ECV at the 34th-35th week could be more effective than ECV at term. Taking into account that the caesarian rate decreased 9% (~10%) with ECV at the 34th week, 10 patients should be treated (NNT) in order to prevent 1 caesarian. This means that only 10 women would need a preterm ECV (instead of receiving a ECV at term) in order to avoid 1 caesarean. However, these results must be reconfirmed by a wider study. The fetal safety and the preterm version must also be verified before recommending a change in the clinical practice. The *Early External Cephalic Version 2 Trial*

The External Version in Modern Obstetrics 201

and they are not clearly related to the version procedure itself. After having analyzed 169 successful versions in a project, it was observed a caesarean rate at delivery 2,25 times higher in comparison with the control group (fetus with spontaneous cephalic presentation). This increase was due to the higher fetal suffering rate and dystocias. It was also proved an increase in the instrumental vaginal birth (Lau et al, 1997). A higher risk of dystocia and fetal suffering in cephalic presentation after version may require a more careful intrapartum

Given the absence of clinical evidence available about the possible adverse effects and their real consequences two meta-analyses have been recently released. The purpose of these analyses was to analyse the adverse effects related to the extreme version procedure, as well as to know its frequency. The most common adverse effects found were the CTGR alterations (between 1% and 47%, depending on the series), specially fetal bradycardia. Most of these alterations are temporary, as they are solved between the first 5 and 60 minutes. The prolonged decelerations that required an emergency caesarean only represented 1,1%, and in all cases the fetuses were born in good condition. There was no increase in the significant risk of nuchal cord in pregnant women subject to external version in comparison with the pregnant women with breech presentation where the version was not performed. The projects describe only 0,054% of cord prolapse cases (Nassar et al, 2006), which is a really low risk compared with the risk in breech or transverse presentation fetus with premature rupture of membranes. The vaginal bleeding after the version occured in approximately three in a thousand pregnants. The incidence of placenta abruption occurred in 0,12%, which is lower than the 0,34%, which represents the at term pregnant overall population. Other reviews, however, did not find any case in its series. Concerning the fetal adverse effects, the femoral fracture also has to be mentioned, occurring one only case among all of

The incidence of fetal demise after the procedure was 1,64 in a thousand versions performed. Thus, it was not clearly related to the external version and none of the cases occurred during the first 24h after the procedure. Anyway, this figure is not higher than antepartum fetal demise (between the 36th and the 40th week) rate (6,2 in a thousand

Concerning the maternal adverse effects found, the external version can be painful for the patient. Approximately 35% of the pregnants suffer mild discomfort during the version and 5% severe pain. The procedure may be stopped for this reason, and it has been observed that when the version fails the pain is higher than when it succeeds. The available data about the use of analgesia during the manoeuvre are still few. 4% suffered tachycardia or palpitations, which were solved one hour later without the use of medication. In less than 2% of the cases, it occurred fetomaternal transfusion. The results did not show any significant differences concerning the start of labour during the 24h after the version compared with the breech presentations where the version was not

only fails

Basically, the data released in the two only meta-analyses reveal a low complication rate and show the external cephalic version as a safe procedure. Nevertheless, new projects

supporting the aforementioned results are strongly needed.

monitoring.

them.

newborns).

performed.

project has been recently approved (in May, 2007). This project will indicate if early ECV is better than ECV at term in order to avoid the caesarean delivery (University of Toronto, 2007).

## **13. ECV: Adverse effects**

The external version is a procedure that is not exempt from potential problems. Nonetheless, if it is properly performed, the risk of complications is low. The Cochrane's systematic review on the external cephalic version in babies at term concluded that the ECV reduced breech presentations and caesareans, without expressing statistically significant differences on perinatal mortality. However, there is not enough evidence to specifically assess the risks related to the procedure.

The available information from the isolated observational studies and classical obstetrics books describe many complications such as hemorrhage, rupture of membranes, umbilical cord arround the fetal neck, placental abruption, start of labour, fetomaternal transfusion, uterine rupture and fetal demise. The most common complication among the described complications is the fetal bradycardia which, as it has already been said, is spontaneously solved in most of the cases when the manoeuvre is stopped. It seems to be due to a temporary fetal hypoxia caused by an increased pressure generated by the uteroplacental blood flow alteration during the version manoeuvres. After the version, the nonreactive CTGR (Cardiotocography Registry), which are temporary as well, are less common. If the bradycardia continues, a caesarean must be urgently performed. For all these reasons, it is recommended to perform the technique in an appropriate room for the immediate care of the aforementioned complications. However, given the low rate of described complications, specifically incomparison with the vaginal delivery, it is not necessary to perform a patient's presurgical preparation (previous absolute diet, premedication prior to general anesthesia or peripheral venous cannulation).

Some temporary Doppler alterations in the umbilical and middle cerebral arteries, as well as an increase in the amniotic fluid volume after the version have also been described The reasons for these alterations are currently unknown. Studies about the posible ECV effects over the fetal blood circulation revealed a reduction in the pulsatility of the middle cerebral artery. However, there were not any modifications in the umbilical artery. Therefore, it does not seem to change the placental blood flow. Furthermore, the reduction in the rate of pulsatility of the middle cerebral artery was more common in multiparous, in posterior placenta or if the procedure was difficult. However, it was not related to the fact that the version was successful (Lau et al, 2000). A recently released article associates the changes in the pulsatility rate with the pressure on the uterine wall during the manoeuvre and also reveals variations in the middle cerebral artery in cases of posterior placenta, as well as in the umbilical artery when it is lateral (Leun et al, 2004). In any case, it seems to be a physiological response and it has never been related to a negative perinatal result.

Once the cephalic version has been completed, many complications have been proved at delivery, such as greater frequency of labor dystocia, risk of fetal suffering, caesarean caused by birth anomalies and induction failure. The reasons for these complications are unknown

project has been recently approved (in May, 2007). This project will indicate if early ECV is better than ECV at term in order to avoid the caesarean delivery (University of Toronto,

The external version is a procedure that is not exempt from potential problems. Nonetheless, if it is properly performed, the risk of complications is low. The Cochrane's systematic review on the external cephalic version in babies at term concluded that the ECV reduced breech presentations and caesareans, without expressing statistically significant differences on perinatal mortality. However, there is not enough evidence to specifically assess the risks

The available information from the isolated observational studies and classical obstetrics books describe many complications such as hemorrhage, rupture of membranes, umbilical cord arround the fetal neck, placental abruption, start of labour, fetomaternal transfusion, uterine rupture and fetal demise. The most common complication among the described complications is the fetal bradycardia which, as it has already been said, is spontaneously solved in most of the cases when the manoeuvre is stopped. It seems to be due to a temporary fetal hypoxia caused by an increased pressure generated by the uteroplacental blood flow alteration during the version manoeuvres. After the version, the nonreactive CTGR (Cardiotocography Registry), which are temporary as well, are less common. If the bradycardia continues, a caesarean must be urgently performed. For all these reasons, it is recommended to perform the technique in an appropriate room for the immediate care of the aforementioned complications. However, given the low rate of described complications, specifically incomparison with the vaginal delivery, it is not necessary to perform a patient's presurgical preparation (previous absolute diet, premedication prior to general anesthesia or

Some temporary Doppler alterations in the umbilical and middle cerebral arteries, as well as an increase in the amniotic fluid volume after the version have also been described The reasons for these alterations are currently unknown. Studies about the posible ECV effects over the fetal blood circulation revealed a reduction in the pulsatility of the middle cerebral artery. However, there were not any modifications in the umbilical artery. Therefore, it does not seem to change the placental blood flow. Furthermore, the reduction in the rate of pulsatility of the middle cerebral artery was more common in multiparous, in posterior placenta or if the procedure was difficult. However, it was not related to the fact that the version was successful (Lau et al, 2000). A recently released article associates the changes in the pulsatility rate with the pressure on the uterine wall during the manoeuvre and also reveals variations in the middle cerebral artery in cases of posterior placenta, as well as in the umbilical artery when it is lateral (Leun et al, 2004). In any case, it seems to be a physiological response and it has never been related to a

Once the cephalic version has been completed, many complications have been proved at delivery, such as greater frequency of labor dystocia, risk of fetal suffering, caesarean caused by birth anomalies and induction failure. The reasons for these complications are unknown

2007).

**13. ECV: Adverse effects** 

related to the procedure.

peripheral venous cannulation).

negative perinatal result.

and they are not clearly related to the version procedure itself. After having analyzed 169 successful versions in a project, it was observed a caesarean rate at delivery 2,25 times higher in comparison with the control group (fetus with spontaneous cephalic presentation). This increase was due to the higher fetal suffering rate and dystocias. It was also proved an increase in the instrumental vaginal birth (Lau et al, 1997). A higher risk of dystocia and fetal suffering in cephalic presentation after version may require a more careful intrapartum monitoring.

Given the absence of clinical evidence available about the possible adverse effects and their real consequences two meta-analyses have been recently released. The purpose of these analyses was to analyse the adverse effects related to the extreme version procedure, as well as to know its frequency. The most common adverse effects found were the CTGR alterations (between 1% and 47%, depending on the series), specially fetal bradycardia. Most of these alterations are temporary, as they are solved between the first 5 and 60 minutes. The prolonged decelerations that required an emergency caesarean only represented 1,1%, and in all cases the fetuses were born in good condition. There was no increase in the significant risk of nuchal cord in pregnant women subject to external version in comparison with the pregnant women with breech presentation where the version was not performed. The projects describe only 0,054% of cord prolapse cases (Nassar et al, 2006), which is a really low risk compared with the risk in breech or transverse presentation fetus with premature rupture of membranes. The vaginal bleeding after the version occured in approximately three in a thousand pregnants. The incidence of placenta abruption occurred in 0,12%, which is lower than the 0,34%, which represents the at term pregnant overall population. Other reviews, however, did not find any case in its series. Concerning the fetal adverse effects, the femoral fracture also has to be mentioned, occurring one only case among all of them. femoral

The incidence of fetal demise after the procedure was 1,64 in a thousand versions performed. Thus, it was not clearly related to the external version and none of the cases occurred during the first 24h after the procedure. Anyway, this figure is not higher than antepartum fetal demise (between the 36th and the 40th week) rate (6,2 in a thousand newborns).

Concerning the maternal adverse effects found, the external version can be painful for the patient. Approximately 35% of the pregnants suffer mild discomfort during the version and 5% severe pain. The procedure may be stopped for this reason, and it has been observed that when the version fails the pain is higher than when it succeeds. The available data about the use of analgesia during the manoeuvre are still few. 4% suffered tachycardia or palpitations, which were solved one hour later without the use of medication. In less than 2% of the cases, it occurred fetomaternal transfusion. The results did not show any significant differences concerning the start of labour during the 24h after the version compared with the breech presentations where the version was not performed.

Basically, the data released in the two only meta-analyses reveal a low complication rate and show the external cephalic version as a safe procedure. Nevertheless, new projects supporting the aforementioned results are strongly needed.

The External Version in Modern Obstetrics 203

Throughout the history, midwives and doctors have used many different techniques referring to the best position to facilitate the cephalic version. However, few articles have been published about this topic in the medical literature. The knee-chest position and the supine position with the pelvis elevated with a wedge-shaped cushion are the most common techniques. The available evidence from the controlled clinical trials is so far

Moxibustion is a type of Chinese medicine which involves burning a herb close to the skin in order to cause a heating sensation. It has also been stated that the acupuncture point called Bladder 67 (BL67) (or *Zhiyin,* according to its Chinese name) placed on the top of the fifth toe can correct breech presentations. How it works is totally unknown, but it seems to stimulate the production of maternal hormones (placental estrogens and prostaglandin) and the uterine contractions, as well as the fetal activity. In spite of not having found any adverse effects, Cochrane did not find enough evidence to prove that the moxibustion might be useful for correcting a breech presentation. The results suggest that moxibustion may be effective to reduce the external cephalic version need and caused a reduction in the use of oxytocin. However, some additional evidence is needed to confirm (or to reject) a benefit with respect to the breech presentation correction (Coyle et

Therefore, there is not enough scientific evidence to recommend neither postural methods nor moxibustion to facilitate the spontaneous cephalic version

The ECV is safe and useful for reducing caesarean rates. The external version success goes from 30% to 80%. The experience of the obstetrician who performed the technique plays a key role in ensuring success (Fandino et al, 2010). An obstetrics service offering daily ECV will be cheaper than a service which does not offer it (James et al, 2001). Tocolycs are recommended to be used during the manoeuvre to reduce adverse effects and increase the

American College of Obstetricians and Gynecologist. Clinical Management Guidelines for

Bost BW. Caesarean delivery on demand: what will it cost? Am J Obstet Gynecol 2003;

Coyle ME, Smith CA, Peat B. Cephalic version by moxibustion for breech presentation.

Danielian PJ, Wang J, Hall MH. Long term outcome by method of delivery of fetuses

Cochrane Database Syst Rev. 2005 Apr 18;(2):CD003928.

Obstetricians-Gynecologists. External cephalic version. Int J Gynecol Obstet 2001;

offering

in breech presentation at term: population based follow up. BMJ 1996;

insufficient to uphold the use of postural methods (Hofmeyr et Kulier, 2000).

al, 2005; Hutton & Hofmeyr, 2006).

(recommendation level A).

**17. Conclusions** 

success rate.

**18. References** 

72: 198-204.

188:1418-23.

312:1.451-3.

Pregnant women should be informed of the possible (although in a low rate) complications of the external version (recommendation level B).
