From the Guidelines
Velamentous cord insertion found on an otherwise normal second trimester ultrasound with normal fetal growth requires increased monitoring but is not an immediate cause for alarm. I recommend continuing routine prenatal care with the addition of serial growth ultrasounds every 4 weeks starting at 24-28 weeks gestation to monitor for growth restriction, as suggested by the most recent guidelines 1. Additionally, a detailed anatomy scan should be performed if not already completed to rule out associated anomalies. For delivery planning, inform your obstetrician about this finding as it may influence delivery management. Velamentous cord insertion occurs when the umbilical vessels separate before reaching the placenta and travel between the amnion and chorion membranes. This condition carries a slightly increased risk of fetal growth restriction, preterm birth, and vasa previa (where fetal vessels cross the internal cervical os), as noted in a recent study 1. While most pregnancies with isolated velamentous cord insertion have normal outcomes, especially when fetal growth is currently normal, the condition warrants vigilance. If growth restriction develops or other complications arise, more frequent monitoring or earlier delivery might become necessary. Patients should report any vaginal bleeding immediately, as this could indicate damage to exposed vessels.
Some key points to consider in the management of velamentous cord insertion include:
- The importance of determining chorionicity and amnionicity in twin pregnancies, as velamentous cord insertion is more common in monochorionic pregnancies 1
- The need for serial sonographic evaluations to screen for twin-twin transfusion syndrome (TTTS) in monochorionic diamniotic twin pregnancies, as velamentous cord insertion is a risk factor for TTTS 1
- The potential benefits and risks of different management options, including expectant management, amnioreduction, and fetoscopic laser photocoagulation of placental anastomoses, in the treatment of TTTS 1
Overall, the management of velamentous cord insertion should be individualized and based on the specific circumstances of each pregnancy, with careful consideration of the potential risks and benefits of different management options.
From the Research
Velamentous Cord Insertion Diagnosis and Implications
- Velamentous cord insertion (VCI) is a rare pathology where the umbilical blood vessels branch before reaching the placenta, making the cord prone to spontaneous internal ruptures 2.
- VCI can be identified during prenatal ultrasound screening, and its early diagnosis is essential to prevent severe complications during labor 2, 3.
- The incidence of VCI varies, with estimated rates ranging from 0.4-11% in singleton pregnancies and higher rates in twin pregnancies 4.
Association with Adverse Perinatal Outcomes
- VCI is associated with an increased risk of adverse perinatal outcomes, including:
- Small-for-gestational-age neonates (relative risk: 1.93,95% CI: 1.54-2.41) 5
- Preeclampsia (relative risk: 1.85,95% CI: 1.01-3.39) 5
- Pregnancy-induced hypertension (relative risk: 1.58,95% CI: 1.46-1.70) 5
- Stillbirth (relative risk: 4.12,95% CI: 1.92-8.87) 5
- Placental abruption (relative risk: 2.94,95% CI: 1.72-5.03) 5
- Preterm delivery (relative risk: 2.14,95% CI: 1.73-2.65) 5
- Emergency cesarean delivery (relative risk: 2.03,95% CI: 1.22-3.38) 5
- The prevalence of VCI is approximately 0.84% in singleton pregnancies, and it is associated with a moderate risk of prematurity and impairment of fetal growth 6.
Screening and Diagnosis
- VCI can be diagnosed prenatally using transabdominal ultrasound or color Doppler 2, 3.
- Screening for VCI using second-trimester transabdominal sonography has good overall accuracy, driven by high specificity 4.
- Early detection and appropriate peripartum management can reduce complications during labor 2.