What are the contraindications for external cephalic version (ECV)?

Contraindications for External Cephalic Version (ECV)

Absolute contraindications for external cephalic version include placenta previa, placental abruption, uterine malformations, regular uterine contractions, premature rupture of membranes, non-reassuring fetal heart rate patterns, and raised intracranial pressure. 1

Absolute Contraindications

• Placental abnormalities:

  • Placenta previa
  • Placental abruption

• Uterine factors:

  • Uterine malformations
  • Regular uterine contractions
  • Previous myometrial incision (classical cesarean)

• Fetal factors:

  • Non-reassuring fetal heart rate patterns
  • Premature rupture of membranes
  • Raised intracranial pressure

• Maternal factors:

  • Active bleeding or bleeding diathesis
  • Severe uncontrolled hypertension

Relative Contraindications

• Previous cesarean delivery: While traditionally considered a contraindication, recent evidence suggests that ECV may be successfully performed in patients with a previous lower segment cesarean delivery with a success rate of 74.1% and no significant increase in complications 2. A 2021 systematic review found ECV success rates ranging from 50-100% in women with previous cesarean deliveries with no reported cases of uterine rupture 3.

• Fetal factors:

  • Oligohydramnios (the only contraindication mentioned consistently across all guidelines) 4
  • Growth restriction
  • Nuchal cord
  • Multiple gestation

• Maternal factors:

  • Obesity
  • Significant maternal disease

Predictors of Successful ECV

Understanding factors that predict successful ECV can help with patient selection:

• Increased amniotic fluid index (AFI) is a significant predictor of successful ECV 1
• Prior vaginal delivery significantly improves success rates 1
• Higher estimated fetal weight correlates with better success rates 1

Clinical Implications

1. Patient Selection: Careful evaluation of contraindications is essential before attempting ECV.

2. Timing: ECV is typically performed after 36 weeks of gestation 1.

3. Monitoring Requirements: Continuous fetal monitoring before, during, and after the procedure is necessary to detect any non-reassuring fetal heart patterns.

4. Success Rates: Overall success rates for ECV range from 28-48.9% in various studies 1, 5.

5. Previous Cesarean Delivery: The evidence suggests that previous lower segment cesarean delivery should not be considered an absolute contraindication, as recent studies show acceptable safety profiles 2, 3.

Practical Considerations

• ECV should be performed in a setting where emergency cesarean delivery is readily available.
• Tocolysis may improve success rates.
• Ultrasound guidance during the procedure helps monitor fetal position and placental location.
• Anti-D immunoglobulin should be administered to Rh-negative women following the procedure to prevent alloimmunization 6.

It's worth noting that there is significant variation in contraindications listed across different guidelines, with a systematic review identifying 39 different contraindications across 60 studies, but with empirical evidence available for only six of them 4. This suggests that many contraindications are based on theoretical concerns rather than robust evidence.