External cephalic version at term--using tocolysis

Factors influencing the effect of external cephalic version: a retrospective nationwide cohort analysis

OBJECTIVE

This study aims to assess the factors associated with the success and failure rate of the external cephalic version (ECV) in breech fetuses. Secondary outcomes were fetal presentation in labor and mode of delivery.

METHODS

This cross-sectional study examined the live birth certificates from 2003 through 2020 from US states and territories that implemented the 2003 revision. A total of 149,671 singleton pregnancies with information about ECV success or failure were included. The outcome was ECV success/failure, while the exposures were possible factors associated with the outcome.

RESULTS

The successful ECV procedures were 96,137 (64.23%). Among the successful ECV procedures, the prevalence of spontaneous vaginal delivery was 71.63%. Among the failed ECV procedures, 24.74% had a cephalic presentation at delivery, but 63.11% of these pregnancies were delivered by cesarean section. Nulliparity, female sex, low fetal weight centile, high pre-pregnancy BMI, high BMI at delivery, and high maternal weight gain during pregnancy were associated with an increased ECV failure (p < 0.001). African American, American Indian and Alaska Native race categories were significant protective factors against ECV failure (p < 0.001). Maternal age had a U-shape risk profile, whereas younger maternal age (< 25 years) and old maternal age (> 40 years) were significant protective factors against ECV failure (p < 0.001).

CONCLUSIONS

A high prevalence of successful ECV procedures and subsequent spontaneous vaginal delivery were found. The present results found nulliparity, maternal race, maternal age, female fetal sex, low fetal weight, and maternal anthropometric features correlated to ECV results. These findings can potentially improve the knowledge about the factors involved in ECV, allowing more informed counseling to the women undergoing this procedure.

Assessment of the Successful External Cephalic Version Prognostic Parameters Effect on Final Mode of Delivery

Aim

This study aims to evaluate the prognostic parameters of successful approach for an external cephalic version (ECV) procedure by considering the vaginal delivery as the optimal mode of delivery.

Methodology

A retrospective cohort study was done during June 2019 in the obstetrics and gynecology department at King Abdulaziz University Hospital. Data were collected between May 2009 and May 2019 and included all pregnant women who were candidates for the ECV. The primary objective was to assess the final mode of delivery in relation to the outcome of ECV followed by the secondary objective which was the prognostic parameters of the ECV procedure (body mass index, amniotic fluid index, parity, estimated fetal weight). Additional variables were maternal age, placental position and ethnicity.

Results

We have studied 86 pregnant women with ECV attempts the overall ECV success rate was for 46 women (59.7%). For the final mode of delivery, after a successful ECV procedure, 40 women (87%) whom had spontaneous vaginal delivery, in association to successful ECV, the prognostic parameters recorded the highest success rate were multiparous 35 (76.1%), body mass index between 25 and 29.9 (53.1%), women older than 30 years old (60.9%), gestational age between 37 to 39.6 weeks (56.5%). Posterior placental location 55.6%, estimated fetal weight more than 2500 (73.9%).

Conclusion

Successful ECV cases have recorded a significant increase in the incidence of spontaneous vaginal delivery and the outcome of ECV which is affected by many prognostic parameters such as parity, maternal age, gestational age, body mass index, amniotic fluid index (AFI) and estimated fetal weight (EFW).  

External Cephalic Version: ACOG Practice Bulletin, Number 221

In the United States, there is a widespread belief that the overall cesarean birth rate is higher than necessary. Efforts are being directed toward decreasing the number of these procedures, in part by encouraging physicians to make changes in their management practices. Because breech presentations are associated with a high rate of cesarean birth, there is renewed interest in techniques such as external cephalic version (ECV) and vaginal breech delivery. The purpose of this document is to provide information about ECV by summarizing the relevant evidence presented in published studies and to make recommendations regarding its use in obstetric practice.

Correlation of Obesity with External Cephalic Version Success among Women with One Previous Cesarean Delivery

Objective  Our aim was to assess the correlation of body mass index (BMI) with the success rate of external cephalic version (ECV) among women with one prior cesarean delivery. Study Design  A cross-sectional study of pregnant women with one previous cesarean delivery who underwent ECV. The relationship between BMI and success rate of ECV was assessed. Adverse outcomes were also compared between women with an ECV attempt, and women who had a repeat cesarean delivery. Data were extracted from the U.S. Natality Database from 2014 to 2017. Pearson's correlation coefficient was performed to assess the relationship between BMI and success rate of ECV. Results  There were 2,329 women with prior cesarean delivery underwent an ECV attempt. The success rate of ECV among the entire cohort was 68.3%. There was no correlation between BMI and success rate of ECV ( r  = 0.024, p  = 0.239). Risks of adverse maternal and neonatal outcomes were similar between the ECV attempt group and the repeat cesarean delivery group. Conclusion  There was no correlation of BMI with the rate of successful ECV among women with one prior cesarean delivery. Given the similar success rates of ECV and adverse outcomes, obese women with one prior cesarean delivery should be offered ECV.

The role of bladder volume in the success of external cephalic version

OBJECTIVE

Numerous studies have evaluated the factors associated with ECV success. Yet, bladder volume has never been examined. We hypothesize that maternal bladder volume may affect ECV success rate. We aim to evaluate the role of maternal bladder volume during external cephalic version (ECV) on the procedure success rates.

STUDY DESIGN

We reviewed prospective collected data of all patients who underwent ECV at our center during 2001-2012. The study group included 100 patients that underwent ECV with bladder volume below 400 ml. These patients were matched to 400 patients that underwent ECV with bladder volume equal or above 400 ml which composed the control group. Maternal and fetal characteristics and outcomes were compared.

RESULTS

ECV was successfully performed in 80/100 (80.0%) of patients in the study group as compared to 257/400 (64.3%) in the control group (P = 0.002). Factors associated with ECV success were older age (P = 0.003), having prior delivery (P < 0.0001), higher amniotic fluid index (AFI) (P = 0.001) and placenta located in the posterior wall (P = 0.001). In a logistic regression analysis, bladder volume was found to be an independent predictor of ECV success Odds radio (OR) for ECV success 2.5 (CI 1.42-4.34). Posterior placenta and higher AFI were found to be an independent predictors of ECV success as well; OR 2.7 (CI 1.74-4.34) and OR 1.07 (CI 1.02-1.13) respectively.

CONCLUSION

ECV is more successful in patient with bladder volume below 400 ml. Amniotic fluid volume and placental location were found as independent predictors of ECV outcome as well.

The impact of maternal body mass index on external cephalic version success

OBJECTIVE

The purpose of this study is to determine the association between body mass index (BMI) and success of ECV.

METHODS

This is a cross-sectional analysis of singleton live births in the USA from 2010 to 2014 using birth certificate data. Patients were assigned a BMI category according to standard WHO classification. Comparisons of success of ECV between the BMI categories were made using chi-square analysis with normal BMI as the reference group. Cochran-Armitage test was performed to look for a trend of decreasing success of ECV as BMI increased. The odds for successful ECV were estimated using multivariate logistic regression analysis, adjusting for possible confounders.

RESULTS

A total of 51,002 patients with documented ECV were available for analysis. There was a decreased success rate for ECV as BMI increased (p < .01). Women with a BMI of 40 kg/m² or greater had a 58.5% success rate of ECV; women with a normal BMI had 65.0% success rate of ECV. Multivariate analyses demonstrated significant decrease in success of ECV in women with BMI of 40 kg/m² or greater (OR 0.621, CI 0.542-0.712). Among women with BMI of 40 kg/m² or greater with successful ECV, 59.5% delivered vaginally. In contrast, 81.0% of women with normal BMI and successful ECV delivered vaginally.

CONCLUSIONS

Morbidly obese women have decreased success rate of ECV as BMI increases and decreased vaginal delivery rates after successful ECV.

External cephalic version with an amniotic fluid index ⩽10: A systematic review

OBJECTIVE

To review the literature and evaluate the role of the amniotic fluid index (AFI) on the success of an external cephalic version (ECV).

STUDY DESIGN

A computerized search of MEDLINE and Cochrane databases were conducted using 'breech', 'version', 'external cephalic version', 'amniotic fluid', and 'amniotic fluid index'. References from the identified publications were manually searched to identify additional relevant articles. Articles from 1987 to 2004 were included.

RESULTS

Of the initial 33 articles discovered, only three remained after exclusions. These articles used different AFI ranges for 'borderline' or 'low-normal' fluid measurements and therefore could not be combined for analysis. All three studies demonstrated a lower success rate of ECV with lower amniotic fluid volume estimates (AFI 5-8, <10, or <8.6), although none reached statistical significance.

CONCLUSION

Due to limited and dissimilar data, it is impossible to define the lower AFI threshold for an unsuccessful ECV compared with the success of a normal AFI. Although not statistically significant, an AFI <10 may correlate with lower success rates for an ECV.

Breech presentation: an audit project as means of pursuing clinical excellence

Clinical audit is an effective quality improvement process to evaluate important clinical issues. Breech presentation is such an issue due to its contribution to the rising caesarean section (CS) rate. We set out to assess the management of breech presentation using, as standards, the delivery suite protocol and national guidelines. Our first audit revealed a low success rate of external cephalic version (ECV) and deficient documentation of written consent for ECV, other aspects of care being satisfactory. The results were presented to a multidisciplinary meeting and disseminated to relevant stakeholders. A re-audit was then performed. It confirmed significant improvement in the documentation of consent for ECV. It also revealed a good detection rate of breech, optimal offer rate of ECV and good neonatal outcome. However, uptake of ECV as well as the success rate could both be improved so as to reduce the CS rate for breech presentation. We discuss options for improving the uptake and success rate for ECV.

External cephalic version: a safe procedure? A systematic review of version-related risks

BACKGROUND

The Term Breech Trial has considerably increased the number of cesareans. External cephalic version (ECV) might be an effective method of lowering the rate of cesareans; its efficacy has been well established. However, although in the absence of anesthesia the risks are thought to be low, most studies have used populations too small to allow definite conclusions on version-related risks.

METHODS

In an attempt to make an inventory of these risks, we have systematically analyzed 44 studies, covering a total of 7377 patients from 1990 to 2002. The studies used were derived from a Medline and Embase search.

RESULTS

The most frequently reported complications were transient abnormal cardiotocography (CTG) patterns (5.7%). Persisting pathological CTG readings (0.37%) and vaginal bleeding occur rarely (0.47%). The incidence of placental abruption was even lower, at 0.12%. Fetomaternal transfusion was absent in five out of seven studies, with a mean incidence of 3.7%. Emergency cesareans were performed in 0.43% of all versions. Perinatal mortality was 0.16%.

CONCLUSIONS

External cephalic version seems to be a safe procedure.

Cell-free fetal deoxyribonucleic acid in maternal circulation as a marker of fetal-maternal hemorrhage in patients undergoing external cephalic version near term

OBJECTIVE

Our aim was to investigate whether external cephalic version performed near term increases the concentration of cell-free fetal deoxyribonucleic acid in maternal plasma.

STUDY DESIGN

Forty-five patients who had singleton male fetuses and were undergoing external cephalic version at or beyond 36 weeks of gestation were recruited during a 20-month period. Maternal venous blood samples were taken before and within 10 minutes after external cephalic version. Deoxyribonucleic acid was extracted from the plasma samples. The amount of fetal deoxyribonucleic acid was quantified by means of the SRY gene on the Y chromosome as a fetal marker. The change in SRY gene concentration before and after external cephalic version was compared by paired sample t test.

RESULTS

There was a significant increase in the concentration of fetal deoxyribonucleic acid in maternal serum after external cephalic version (before, 296 +/- 209 copies per milliliter; after, 369 +/- 228 copies per milliliter; P =.014). This increase in the concentration of deoxyribonucleic acid was most profound among the nulliparous patients after a successful version and in the presence of a posterior placenta. The location of the placenta was found to be the most significant factor accounting for the change in the deoxyribonucleic acid concentration.

CONCLUSIONS

External cephalic version near term imposed a significant disturbance to the maternalplacental interface. Fetal deoxyribonucleic acid is a sensitive marker that is useful in the assessment of subclinical fetal-maternal hemorrhage.

A survey of pregnant women's attitude towards breech delivery and external cephalic version

A structured interview survey was carried out in 150 women who came for their first antenatal visit in a university hospital in Hong Kong between June and July 1998. Their opinions and perceptions of fetal and maternal safeties on different modes of delivery for both cephalic and breech presentation, and external cephalic version (ECV) were surveyed. Their decisions on the management of term breech-presenting pregnancy were examined. Most women (92%) preferred vaginal delivery to Caesarean delivery (CS) in case of cephalic presentation, mainly because it was a natural way of parturition. They perceived that vaginal delivery was safer than CS for both mothers and babies, but the reverse was true for breech presentation. About 82% chose ECV as the first choice of managing breech presentation, mainly because a successful version allowed a natural way of delivery. Only 2% of women considered ECV ineffective, and 13.3% and 18.7% considered it not safe for mothers and fetuses respectively. Therefore, ECV should be an available option in all obstetric units. Adequate counselling and explanation would improve the acceptance of ECV.

Significance of success rate of external cephalic versions and vaginal breech deliveries in counseling women with breech presentation at term

OBJECTIVE

To appreciate the role of success rates of external cephalic versions and breech deliveries, in order to assess the risk reduction in women with breech presentation at term.

STUDY DESIGN

We reviewed the patient files of all women with breech presentation whom had an attempt of external cephalic version (ECV) at term. Most of the ECVs were performed under intravenous ritodrine infusion. All women had a trial of labor (TOL) as long as they did not meet one or more of the exclusion criteria of vaginal delivery. Success rates of ECV and TOL were assessed, and statistical analysis was performed by using the student t-test for continuous data, and the Chi-square and Fisher's exact tests for categorical data. Statistically significant differences required a P value of <0.05.

RESULTS

Of all women with breech presentation at term and not in labor, who had no contraindication for an ECV, 164 consented and were included in the study. The success rate of ECV was 30% (22/74) and 67% (60/90) for nulliparae and multiparae, respectively. Multiparity was the only significant positive predicting variable for ECV success (OR=4.73, 95% CI 4.19-5.27, P=0.00001). Of all the women that underwent a successful ECV, 18/22 primiparae (82%), and 52/60 multiparae (87%) had a vaginal delivery, compared to only 52% of the primiparae and 63% of the multiparae that reached labor with a breech presentation. There were no significant perinatal complications except for one case of mild placental abruption. In the primiparous women, ECV decreased the chance of cesarean delivery by only 9% (P=0.2), compared to a 16% decrease in the multiparae (P=0.019).

CONCLUSIONS

When counseling women with breech presentation at term, complete information is needed for consent, and should take into account the success rate of ECVs and of vaginal breech deliveries in the specific center.

Outcome of labour after successful external cephalic version at term complicated by isolated transient fetal bradycardia

OBJECTIVES

To investigate factors associated with the occurrence of transient fetal bradycardia after external cephalic version, and labour outcome after isolated transient fetal bradycardia.

DESIGN

Cohort study.

SETTING

Teaching hospital with a policy of offering external cephalic version for breech presentation at or beyond 36 weeks of gestation.

POPULATION

Four hundred and twenty-nine external cephalic versions performed over a 5-year period.

METHODS

Between group differences were compared with the unpaired t test or the chi2 test. Logistic regression analysis was performed to exclude confounding effects.

MAIN OUTCOME MEASURES

Incidence of caesarean section for fetal distress.

RESULTS

Transient fetal bradycardia occurred in 8.4% of external cephalic versions, and was associated with a successful version (OR 16.45, P < 0.001), a difficult procedure (OR 3.70, P = 0.001), and nulliparity (OR 2.83, P = 0.007). The incidence of intrapartum caesarean section for fetal distress was 16.7% in pregnancies with transient fetal bradycardia, compared with 7.9% in those without (OR 2.34, 95% CI 0.81, 6.71).

CONCLUSIONS

Transient fetal bradycardia after external cephalic version may be associated with a higher risk of intrapartum caesarean section for fetal distress.

Predictors of successful external cephalic version at term: a prospective study

OBJECTIVE

To investigate clinical and ultrasonographic predictors of outcome of external cephalic version at term.

DESIGN

Prospective observational study.

SETTING

University obstetric unit.

POPULATION

All external cephalic versions performed over two years (n = 243).

METHODS

Nineteen different clinical and ultrasonographic variables were recorded before each procedure. The ability of each of the 19 variables to predict the success or failure of external cephalic version was assessed by univariate analysis. The study population was then divided into two subgroups of 129 and 114 patients by random allocation using computer generated numbers. Logistic regression was performed in each subgroup to assess the relative importance and independence of the important variables. The derived regression models were then applied to the other subgroup of patients to assess accuracy and reproducibility.

RESULTS

The overall success rate of the procedure was 69.5%. Both regression models identified the same three variables as independent predictors of failed versions: 1. presenting part engaged; 2. difficult to palpate the fetal head, and 3. a tense uterus on palpation. The two models correctly predicted 75.2% and 84.2% of outcomes in the other subgroup. If uterine tone, which was assessed after administration of tocolytic, was excluded from the analysis, the other two factors remained in the models, with the addition of nulliparity as a significant predictor of failed external cephalic version. The chance of success of external cephalic version in the original 243 women was found to be < 20% if two of these variables were present, 0% if all three were present, and 94% if none were present.

CONCLUSIONS

The outcome of external cephalic version can be predicted by easily available clinical parameters.

Pregnancy outcome after successful external cephalic version for breech presentation at term

OBJECTIVE

Our purpose was to review the outcome of pregnancies after external cephalic version at term, in particular the incidence and indications of intrapartum cesarean section after successful external cephalic version.

STUDY DESIGN

A prospective study was performed of 241 term pregnancies that had a total of 243 external cephalic versions. Each case with successful external cephalic version was matched to two control cases with cephalic presentation to compare pregnancy outcome.

RESULTS

External cephalic version was successful in 169 attempts (69.5%), of which 7 (4.1%) reverted to breech presentation. There was one case of abruptio placentae and eight cases (3.3%) of transient fetal bradycardia after the procedure. Among those who had a successful external cephalic version, the incidence of intrapartum cesarean section was 16.9%, which was 2.25 times higher than that of the control group (p < 0.005). This large number of abdominal deliveries was due to a significantly higher incidence of fetal distress and dystocic labor. The incidence of augmentation of labor was also significantly higher in the study group (37.7% vs 27.6%, p < 0.05).

CONCLUSION

Pregnancies after a successful external cephalic version at term are not the same as those with cephalic presentation. They are at higher risk of both dystocic labor and fetal distress and therefore require close intrapartum monitoring.