Randomized control trial of external cephalic version with tocolysis in late pregnancy

Abstract

Two strategies have evolved for managing term intrapartum breech presentation: routine cesarean section and selective vaginal delivery. Both result in an exceedingly high cesarean section rate and neither attacks the frequency of breech presentation in labor. External cephalic version under tocolysis (ECV-T) offers an altemative. In a randomized, controlled trial, we tested ECV-T (terbutaline) at 37 to 39 weeks' gestation on 51 low-risk patients. Normal real time B-scan examination and reactive nonstress test were prerequisites. Rigid exciusion criteria were employed. Version succeeded in 68% of the attempts and all presented in labor with a vertex presentation. All those in whom version falled (32%) presented in labor with a breech presentation and 75% were delivered by cesarean section. Nulliparity, maternal obesity, engagement of the breech, and uterine anomaly prejudiced success. In the control group (version not attempted), 18% converted spontaneously to vertex while 82% persisted with a breech presentation. Despite a liberal policy concerning vaginal breech delivery, 85% of the patients (entire series) with breech presentation during labor were delivered by cesarean section. Transient fetal heart rate (FHR) deceleration was noted during version in 36% of the attempts (24% of successes and 63% of failures) but invariably responded when manipulation ceased. However, fetal distress immediately following successful version necessitated intervention in one patient who ultimately had a normal labor and vaginal delivery of a healthy infant. There were no other untoward maternal, fetal, or neonatal complications and outcome was uniformly good. These preliminary data suggest that ECV-T late in pregnancy reduces (p < 0.01) the incidence of intrapartum breech presentation. The effect on the cesarean section rate depends on the strategy for management of the breech presentation. Uterine relaxants appear to facilitate the procedure. Although we experienced no adverse outcomes, larger series are required to determine safety of ECV-T.