Since the Term Breech Trial, the management of term singleton fetuses in breech presentation has changed to planned caesarean delivery as the recommended mode of delivery.1,2 External cephalic version is a safe and effective method to reduce the frequency of breech presentation at term and has been shown to lower the caesarean delivery rate for breech position by 50%.3 In our center, external cephalic version is part of the standard care for women with a term breech lie. The success rate of external cephalic version has been reported to vary between 35% and 86%,4 with a success rate of 47% in multiparous and 35% in primiparous women in our center. There is a documented positive association between estimated amniotic fluid volume and the success rate of external cephalic version.5 In 1994, a report on six cases of failed external cephalic version with a 100% success rate of renewed external cephalic version after amnioinfusion was published by Benifla et al6 The aim of our study was to see whether we could obtain similar results in a prospective study to evaluate the effectiveness of antepartum amnioinfusion to facilitate external cephalic version after initial failure.
MATERIALS AND METHODS
Women with a failed external cephalic version and an amniotic fluid index (AFI) less than 15 cm were offered amnioinfusion. They were recruited from our outpatient clinic as well as through referrals from midwives. The study was conducted from August 2003 to August 2004. Inclusion criteria were a singleton pregnancy, breech presentation of at least 36 weeks of gestation, and no major anomalies on ultrasonographic evaluation. Whether or not the breech was mobile was not taken into account, because we aimed to evaluate the success rate of all external cephalic versions and not only those who were most likely to succeed.
Ultrasound-guided transabdominal amnioinfusion was performed using an 18G needle. Warm Ringers' lactate was infused until the AFI reached 15 cm, with a maximum of 1 liter. External cephalic version was attempted again the same day. All women received tocolysis with indomethacin during amnioinfusion and ritodrine during external cephalic version. All women were monitored and delivered in our center. Due to the lack of data from the literature, we decided to perform a study of 10 cases, after which we planned to design a blinded randomized controlled trial.
The 95% confidence interval for the success rate was calculated using the Adjusted Wald method for small-sample completion rates.7 The study was approved by the Leiden Medical University institutional review board.
Seven women participated in the study. Mean gestational age was 37+3 weeks (range 36+4 to 38+3). Three women were primiparous, and four were multiparous. Mean AFI before infusion was 9 cm (range 4–13 cm). A mean amount of 1,000 mL (range 700–1,000 mL) of Ringers' solution was infused per procedure (Table 1). All amnioinfusions were successful and uncomplicated. None of the repeat external cephalic versions after amnioinfusion were successful (95% confidence interval 0–0.322).
Transabdominal filling of the amniotic cavity with fluid provides the fetus with more space to move and could be expected to facilitate external cephalic version in breech presentation. However, our findings did not concur with this assumption, in contrast to the previous study by Benifla et al.6 Our small series was an unselected group of consecutive patients eligible for external cephalic version and included a mix of both primiparous and multiparous women. The paper by Benifla does not describe their inclusion criteria.
We can only speculate on the reasons for our high failure rate. Experienced perinatologists performed the external cephalic version procedures. Perhaps we should have waited longer after the amnioinfusion before attempting external cephalic version, thus giving the uterus more time to adjust to the increased amniotic fluid volume. Benifla et al6 reported an average interval of 1 day. In our patients, we only performed the external cephalic version in the absence of any uterine contractions. The study by Benifla et al6 is incorporated in the Cochrane review on external cephalic version.3 We searched the literature using MEDLINE (January 1966–June 2005) and EMBASE (January 1980–June 2005) with key words “external cephalic version,” “ECV,” and “amnioinfusion” without language restrictions. We were surprised to find no other published reports on amnioinfusion for failed external cephalic version, despite the renewed interest in this topic since the Term Breech Trial. A possibility could be that others have had similar disappointing results with attempting to repeat the study but chose not to publish. There were no complications due to amnioinfusion in our study, but rare complications of this procedure cannot be assessed given our small sample size.
In our study, amnioinfusion did not facilitate external cephalic version after an initial failed attempt. This is in sharp contrast with the only other study on this subject. Further research into various causes for failure and subsequent solution is warranted.
1. Hannah ME, Hannah WJ, Hewson SA, Hodnett ED, Saigal S, Willan AR; for the Term Breech Collaborative Group. Planned caesarean section versus planned vaginal birth for breech presentation at term: a randomized multicentre trial. Lancet 2000;356:1375–83.
2. Mode of term singleton breech delivery. ACOG Committee Opinion No. 265. American College of Obstetricians and Gynecologists. Obstet Gynecol 2001;98:1189–90.
3. Hofmeyr GJ, Gyte G. Interventions to help external cephalic version for breech presentation at term (Cochrane Review). In: The Cochrane Library, Issue 1, 2004. Oxford: Update Software.
4. American College of Obstetricians and Gynecologists. External cephalic version. ACOG Practice Bulletin 13. Washington, DC: ACOG; 2000.
5. Boucher M, Bujold E, Marquette GP, Vezina Y. The relationship between amniotic fluid index and successful external cephalic version: a 14-year experience. Am J Obstet Gynecol 2003;189:751–4.
6. Benifla JL, Goffinet F, Darai E, Madelenat P. Antepartum transabdominal amnioinfusion to facilitate external cephalic version after initial failure. Obstet Gynecol 1994;84:1041–2.
7. Agresti A, Coull B. Approximate is better than “exact” for interval estimation of binomial proportions. Am Stat 1998;52:119–26.