velamentous cord insertion
Pronunciation: vel-uh-MEN-tus
Abnormal umbilical cord attachment where vessels insert into the membranes rather than directly into the placental disc.
Full Definition
Velamentous cord insertion is an abnormal placental condition where the umbilical vessels separate before reaching the placenta and course through the membranes (chorioamniotic membranes) before inserting into the placental disc. This occurs in approximately 1% of singleton pregnancies and up to 15% of multiple pregnancies. The condition creates vulnerability because the umbilical vessels lack the protective Wharton's jelly when they traverse the membranes. Complications include vasa previa (when vessels cross the internal cervical os), vessel rupture during membrane rupture, fetal hemorrhage, and increased risk of intrauterine growth restriction. Diagnosis is made by ultrasound, and management depends on the presence of associated conditions such as vasa previa, which may require cesarean delivery.
Usage
Usage note: May be associated with vasa previa; requires careful evaluation of vessel course relative to cervix.
In Context
- "Color Doppler ultrasound revealed velamentous cord insertion with vessels coursing through the membranes." — Ultrasound report
- "The velamentous cord insertion was complicated by vasa previa requiring planned cesarean delivery." — Delivery planning note