Management of Velamentous Umbilical Cord Insertion in Pregnancy
For pregnancies with velamentous umbilical cord insertion, cesarean delivery should be considered based on the entire clinical scenario, particularly when associated with other risk factors such as vasa previa.
Understanding Velamentous Cord Insertion
Velamentous cord insertion (VCI) is an abnormal placental cord insertion where umbilical vessels diverge and travel between the amnion and chorion before reaching the placenta, leaving vessels unprotected and exposed to pressure and injury during pregnancy and labor.
Risk Factors and Prevalence
- Occurs in approximately 1% of singleton pregnancies 1
- More common in:
Diagnostic Approach
Early detection is crucial for appropriate management:
- Systematic assessment of placental cord insertion site during routine second-trimester ultrasound (18-22 weeks) 1
- Can be diagnosed by ultrasonography with 67% sensitivity and 100% specificity in the second trimester 1
- Color Doppler ultrasound enhances visualization of vessels traversing membranes 4
Delivery Planning Algorithm
Step 1: Risk Assessment
Evaluate for additional risk factors that significantly increase complications:
- Presence of vasa previa (significantly higher risk with VCI) 3, 5
- Single umbilical artery 5
- Lobed placenta 5
- Placenta previa 5
- Evidence of fetal growth restriction 2
Step 2: Mode of Delivery Decision
Cesarean Delivery Recommended When:
- VCI with coexistent vasa previa (absolute indication) 6
- VCI with evidence of fetal growth restriction 2
- VCI with abnormal umbilical artery Doppler studies 3
- VCI in monochorionic twin pregnancies 3
- VCI with polyhydramnios 2
- VCI with placenta previa 5
Vaginal Delivery May Be Considered When:
- Isolated VCI without other risk factors
- Normal fetal growth
- Normal umbilical artery Doppler studies
- No evidence of vasa previa
Evidence-Based Recommendations
The Society for Maternal-Fetal Medicine suggests that for pregnancies with fetal growth restriction complicated by absent/reversed end-diastolic velocity, cesarean delivery should be considered based on the entire clinical scenario (Grade 2C) 3. This recommendation can be extended to VCI cases with associated complications.
Velamentous cord insertion increases the risk of:
- Intrauterine growth restriction (OR = 4.3) 2
- Preterm birth (OR = 4.6) 2
- Cesarean delivery (OR = 3.3) 2
- Low Apgar score (OR = 2.3) 2
- Perinatal mortality (OR = 4.07) 2
Intrapartum Management
For Planned Cesarean Delivery:
- Schedule delivery at 37-39 weeks depending on associated complications
- Consider antenatal corticosteroids if delivery is anticipated before 34 weeks 3
- Ensure neonatal team presence at delivery
- Careful handling of placenta and cord during delivery
For Vaginal Delivery (if selected):
- Continuous fetal monitoring
- Avoid artificial rupture of membranes when possible
- Be prepared for emergency cesarean if fetal distress occurs
- Have blood products available (risk of vessel rupture)
Important Caveats
- High vigilance needed: VCI is an independent risk factor for perinatal mortality (OR = 4.07) 2
- Vasa previa detection is critical: When VCI coexists with vasa previa, cesarean delivery is mandatory before labor 6
- Routine identification: The placental cord insertion site should be routinely identified during second-trimester ultrasound 5
- Early diagnosis matters: Prenatal detection allows for planned delivery and reduces emergency cesarean sections 1
The evidence strongly suggests that VCI significantly increases obstetric complications and adverse outcomes. While isolated VCI without other risk factors may permit vaginal delivery, the presence of additional risk factors warrants serious consideration of cesarean delivery to reduce perinatal morbidity and mortality.