What is ECV (External Cephalic Version)?
ECV (External Cephalic Version) is a manual procedure performed by a healthcare provider to turn a breech-presenting fetus to a head-down (cephalic) position by applying external pressure to the mother's abdomen, typically performed at or after 36-37 weeks of gestation. 1, 2, 3
Purpose and Clinical Context
- ECV is performed to reduce the rate of breech presentation at birth, which in turn decreases the need for cesarean sections while avoiding the risks associated with vaginal breech delivery 3, 4
- The procedure is grounded in evidence that vaginal breech birth presents greater short-term risks for babies than cesarean section, but cesarean section also carries maternal risks that can be avoided through successful version 4
When ECV is Performed
- ECV should be attempted from 36 weeks gestation onward, with most procedures performed at 37±3 weeks 2, 3
- ECV before 37 weeks increases the rate of cephalic presentation at birth but carries a small increased risk of moderate prematurity 3
- The procedure must be performed with immediate access to an operating room for emergency cesarean section 3
Success Rates and Predictive Factors
- Success rates range from 46% to 82.5% depending on patient selection and technique 1, 5, 2
- Multiparity is the strongest predictor of success (ORadjusted=3.03) 2, 3
- Maternal obesity significantly reduces success rates, with BMI>40 kg/m² having an ORadjusted=0.09 compared to BMI<25 kg/m² 2
- Flexed type of breech presentation is associated with higher success rates 1
Use of Tocolysis
- Parenteral tocolysis (β-mimetic or atosiban) should be used for ECV attempts at term as it increases success rates, achieves higher rates of cephalic presentation in labor, and lowers cesarean section rates 3
Safety Profile and Monitoring
- Complications occur in approximately 5.9% of cases and include: vaginal bleeding (2.5%), fetal bradycardia (2.8%), preterm rupture of membranes (0.3%), and cord prolapse (0.3%) 2
- Cardiotocography must be performed before and for 30 minutes after the procedure due to increased risk of transient fetal heart rate abnormalities 3
- There are no serious fetal or maternal complications when appropriate patient selection is used 1
- ECV is associated with increased transient FHR abnormalities but not severe maternal or perinatal morbidity 3
Post-Procedure Considerations
- RH-negative women require systematic RH prophylaxis after ECV attempt 3
- Routine Kleihauer testing is not recommended as the risk of significant fetomaternal hemorrhage (>30mL) is very low (<0.1%) 3
- Delayed cardiotocography after successful ECV is not recommended 3
Delivery Outcomes After Successful ECV
- Following successful ECV, the cesarean delivery rate is 22.2%, spontaneous vaginal delivery rate is 52.1%, and instrumented vaginal delivery rate is 25.7% 2
- Successful ECV is associated with a 6.29% increase in instrumented delivery rate (OR=1.63) but does not modify overall cesarean or spontaneous delivery rates 2
- The rate of cesarean section following successful ECV can be as low as 12.5% with appropriate patient selection 1