From the Guidelines
A velamentous cord insertion identified on a routine second trimester ultrasound requires close monitoring throughout pregnancy to mitigate the increased risk of adverse outcomes, including growth restriction, preterm birth, and cesarean delivery, as highlighted in the most recent study by 1. The condition of velamentous cord insertion occurs when the umbilical cord attaches to the fetal membranes rather than directly to the placental mass, causing blood vessels to travel unprotected through membranes before reaching the placenta. This increases risks of vessel compression, rupture, or bleeding, particularly if vessels cross the cervical os (vasa previa) 1.
Key Considerations
- The risk of adverse outcomes is higher in multiple gestations, with velamentous cord insertion present in up to 22% of monochorionic (MC) twins, as noted in the study by 1.
- Velamentous cord insertion in MC twins increases the risk of small for gestational age and selective fetal growth restriction (sFGR), lower gestational age at birth, and intrauterine fetal demise 1.
- There is also a higher frequency of vasa previa when a velamentous cord insertion is found, especially in MC pregnancies, which necessitates careful evaluation and monitoring 1.
Recommended Monitoring and Management
- Follow-up ultrasounds every 4 weeks to monitor fetal growth and placental function are recommended, as outlined in the guidelines by 1.
- More frequent prenatal visits in the third trimester and possibly a detailed ultrasound with color Doppler to assess blood flow may be advised by the obstetrician.
- Prompt reporting of any vaginal bleeding is crucial, as it could indicate vessel damage.
- Delivery planning may include scheduling a cesarean section if vasa previa is present, though vaginal delivery remains possible in uncomplicated cases. It is essential to discuss with the healthcare provider about creating a comprehensive monitoring plan specific to the situation, taking into account the most recent evidence and guidelines, such as those provided by 1 and 1.
From the Research
Velamentous Cord Insertion Diagnosis
- Velamentous cord insertion is a rare pathology where the umbilical blood vessels branch before reaching the placenta, making the cord prone to spontaneous internal ruptures 2.
- This condition can be diagnosed prenatally using imaging techniques such as transabdominal ultrasound or color Doppler, even from the second trimester 2, 3, 4.
- The incidence of velamentous cord insertion is reported to be around 1% in singleton pregnancies 3, 5, 6.
Detection Methods
- Color Doppler ultrasound can reliably detect velamentous insertion of the umbilical cord prenatally 3.
- Gray-scale and color Doppler ultrasound can be used to identify the placental cord insertion site, with a high success rate of 99% 3.
- 3D ultrasound has limited value in evaluating the placental cord insertion site due to poor-quality resolution and time-consuming process 3.
- Transvaginal ultrasound with color and power Doppler can be used to diagnose velamentous marginal umbilical cord insertion associated with vasa praevia 5.
Clinical Significance
- Velamentous cord insertion is associated with several obstetric complications, including fetal growth restriction, prematurity, congenital anomalies, low Apgar scores, fetal bleeding, and retained placenta 3, 5, 6.
- Early detection and appropriate peripartum management can highly reduce complications during labor 2.
- Systematic assessment of the placental cord insertion site at routine obstetric ultrasound can identify pregnancies with velamentous insertion and those at risk for obstetric complications 3, 6.