Management of Velamentous Cord Insertion in Pregnancy
Cesarean delivery is not routinely necessary for all cases of velamentous cord insertion, but should be performed when velamentous cord insertion is associated with vasa previa or other high-risk complications.
Understanding Velamentous Cord Insertion
Velamentous cord insertion is an abnormal placental cord insertion where umbilical vessels diverge and travel between the amnion and chorion before reaching the placental margin. This condition:
- Occurs in approximately 1% of singleton pregnancies 1
- Is more common in multiple gestations, with up to 22% prevalence in monochorionic twins 2
- Can be diagnosed prenatally by ultrasound with high specificity during second trimester anatomy scan 1
Risk Factors for Velamentous Cord Insertion
- Multiple gestations (OR = 9.2) 3
- Infertility treatments (OR = 4.3) 3
- Chronic hypertension (OR = 2.2) 3
Associated Complications
Velamentous cord insertion is associated with increased risk of:
- Small-for-gestational-age neonates (RR = 1.93) 4
- Preeclampsia (RR = 1.85) 4
- Stillbirth (RR = 4.12) 4
- Placental abruption (RR = 2.94) 4
- Preterm delivery (RR = 2.14) 4
- Emergency cesarean delivery (RR = 2.03) 4
- Low Apgar scores 4
Management Algorithm for Velamentous Cord Insertion
1. Prenatal Detection and Assessment
- Document placental cord insertion during routine second trimester anatomy scan (18-22 weeks) 2
- Perform detailed ultrasound evaluation with color Doppler to assess:
- Distance from cord insertion to placental edge
- Presence of vasa previa (vessels crossing near internal cervical os)
- Fetal growth parameters
- Amniotic fluid volume
2. Surveillance for Isolated Velamentous Cord Insertion
- Increased ultrasound surveillance for fetal growth (every 3-4 weeks)
- Assessment of umbilical artery Doppler after 20 weeks 2
- Calculate and document estimated fetal weight discrepancy at each scan 2
3. Delivery Planning
When cesarean delivery IS indicated:
- Presence of vasa previa (highest risk complication) 5
- Fetal growth restriction with abnormal Doppler studies 2
- Non-reassuring fetal status during labor 1
When vaginal delivery may be appropriate:
- Isolated velamentous cord insertion without vasa previa
- Normal fetal growth
- Reassuring fetal status
4. Timing of Delivery
For cases requiring cesarean delivery:
- With vasa previa: Planned cesarean at 34-36 weeks after antenatal corticosteroids at 32 weeks 5
- Without vasa previa but with other complications: Individualized timing based on severity of complications
Special Considerations
Vasa Previa: The most dangerous complication of velamentous cord insertion. Rupture of membranes can lead to fetal hemorrhage with high mortality. Always rule out vasa previa when velamentous cord insertion is identified 5
Multiple Gestations: Higher prevalence of velamentous cord insertion (up to 22% in monochorionic twins). Requires more intensive monitoring and may influence delivery planning 2
Intrapartum Management: If velamentous cord insertion without vasa previa is present and vaginal delivery is attempted, avoid artificial rupture of membranes and use continuous fetal monitoring 3
Conclusion
The presence of velamentous cord insertion alone does not mandate cesarean delivery. The decision should be based on associated complications, particularly vasa previa, which represents a clear indication for planned cesarean delivery before the onset of labor. Early prenatal detection through routine ultrasound assessment of cord insertion allows for appropriate surveillance and delivery planning, potentially reducing emergency cesarean sections and improving outcomes 6, 4.