**9. ECV: Contraindications**

The Spanish, British and Canadian obstetrics and gynaecology association agree that there is not enough evidence to draw up a contraindication list. Nevertheless, they do take into account some situations that seem to be related to an increase in morbidity and mortality. Among them, the following can be considered:


Severe uterine anomaly.

196 From Preconception to Postpartum

If this technique does not succeed and the fetus returns to breech presentation, the version can be repeated after 5-7 days. It is estimated that 5-10% of the fetus return to the presentation previous to the version, as the cause that generated the abnormal presentation continues. This spontaneous reversion is more common in multiparous than in nulliparous mothers. However, there is no scientific evidence recommending the immediate labor induction in order to reduce the possibility of reversion (American College of Obstetricians

Rh (-) patients will be given anti-D gamma globulin after the version, as it is estimated that

 Ultrasound scanning to reveal any contraindications in order to perform the method instead of a vaginal delivery. It will also be useful to know: the fetal estimated weight, the fetus presentation, position and situation, the amniotic fluid index, and the location of the placenta and of the umbilical cord. Using an ultrasound scan while performing

Performance of the procedure near a operating theatre equipped for an emergency

The pregnant woman must be placed in the supine position, in semi-Fowler and with a

Insertion of an intravenous (IV) to perfuse uterine relaxants (a ritodrine dose of 200

The Spanish, British and Canadian obstetrics and gynaecology association agree that there is not enough evidence to draw up a contraindication list. Nevertheless, they do take into account some situations that seem to be related to an increase in morbidity and mortality.

The following prerequisites are necessary before performing an external version:

Previous checking of fetal wellbeing (reactive NST [Non Stressing Test]).

and Gynecologist [ACOG], 2001).

Absence of contraindications.

**8. ECV: Prerequisites** 

μg/min).

 Placenta praevia Abruptio placentae

Oligohydramnios

 Intrauterine fetal demise. Severe malformations. Rupture of membranes. Multiple gestation. RH isoimmunization.

**9. ECV: Contraindications** 

the risk of fetomaternal hemorrhage is approximately 1%.

Informed consent signed by the pregnant.

the maneuver is very advantageous.

Among them, the following can be considered:

Vaginal bleeding in the previous seven days.

caesarean, in case of potential severe complications.

light Trendelenburg in order to facilitate the buttocks move.

Fetal compromise or suspected fetal compromise (abnormal RGTC)


Determining which situations could be considered as relative contraindications is more difficult, but the following are some of them:


#### **10. ECV: Predictors and success rate**

The spontaneous version rate in nulliparous women, as of the 36th week, is 8%. However, if the version is not successful, this rate is only 5%. The probability of reversion after a successful version is only 5%.

Depending on the series, the external version success oscillates between 30-80%. This success also depends on the race, parity, uterine tone, amniotic fluid volume, cephalic engagement, possibility of palpation of cephalic pole and use of tocolytics. The highest success rates have been observed in multiparous nonwhite women with relaxed uterus, when the breech presentation is not fixed and the cephalic pole can be easily palpated (Lau et al, 1997). This would be the optimal condition in order to obtain a successful version.

Many authors have been looking for patterns aiming at predicting the cephalic version success or failure (Newman et al, 1993). Those factors considered as the most significant tones in a failed external version are the following: the cephalic pole palpation, the engagement presentation level and a tense uterus when palpated. When these factors are missing, the probability of a failed external version is only 6%. However, the failure probability increases over 80% if more than one of these three factors occurs. Thus, in a group composed of 243 pregnant women subject to an external cephalic version, the ECV was successful in 94% of the cases when none of these factors occurred, as well as in at least 20% of the cases if two of those factors occurred and 0% of the cases if the three factors took place.

Nevertheless, other factors considered as significant independent predictors in the past, as the placental location, the backbone position, the breech type, the maternal body mass index and the fetal weight seem to be less significant if the three factors mentioned above are controlled (they are not independent factors). However, it must be taken into account that the usefulness of these indicators is still awaiting confirmation by further research. these still

The External Version in Modern Obstetrics 199

trying the external cephalic version or the reversion after a successful external cephalic

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

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

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

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

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*

version are less common at term.

probability overcomes the version risk.

ECV.

level (Hutton et al, 2003).

higher risks, no procedure can be currently recommended.

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 higher number of spontaneous revisions.

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