Effectiveness of epidural anesthesia for external cephalic version (ECV).

OBJECTIVE: The Cochrane review conducted in 2001 re-established the usefulness of external cephalic version (ECV). The success rate for ECV using epidural anesthesia or spinal anesthesia is reported to be 35 to 86%. In this study, we examined the effectiveness of epidural anesthesia for ECV.

STUDY DESIGN: A retrospective cohort study was conducted of pregnant women who were at 35 to 36 weeks of gestation between 2001 and June 2009, with a single fetus, non-cephalic presentation and without non-reassuring fetal status. The subjects were ultrasonographically examined for placental location, presence/absence of nuchal cord and amniotic fluid volume. Those with placenta previa, early rupture of membranes, uterine anomaly or severe fetal anomaly and those in whom delivery was initiated were excluded from the study. The study protocol was approved by the institutional ethics committee, and written informed consent was obtained for all procedures described in the protocol. The success rate for ECV was compared between the anesthesia and non-anesthesia groups. Analysis was also performed to identify factors contributing to successful ECV.

RESULT: There were 86 women with non-cephalic presentation who underwent ECV during the study period. The non-anesthesia group consisted of 34 women in whom ritodrine hydrochloride, a tocolytic agent, was administered alone, and 52 women in whom a tocolytic agent and epidural anesthesia were used constituted the anesthesia group. There were no significant differences between the two groups in terms of age, parity, body mass index and placental location. The success rate for ECV was 55.9% (19/34 patients) in the non-anesthesia group and 78.8% (41/52 patients) in the anesthesia group, showing a significant difference between the two groups (odds ratio 1.75, 95% confidence interval 1.26 to 2.44). Analysis was also performed to identify factors determining successful ECV other than epidural anesthesia from among age, parity, body mass index, placental location, presence/absence of uterine myoma, nuchal code and previous cesarean delivery; however, none of the factors identified was found to be a significant determinant factor.

CONCLUSION: The use of epidural anesthesia significantly increases the success rate for ECV for breech presentation.