velamentous cord insertion
Pronunciation: vel-ah-MEN-tus
An abnormal umbilical cord attachment where vessels insert into fetal membranes rather than directly into the placenta.
Full Definition
Velamentous cord insertion is a placental abnormality where the umbilical cord vessels separate before reaching the placenta and travel through the fetal membranes (chorioamnion) instead of being protected by Wharton's jelly. This leaves the vessels vulnerable to compression and rupture. The condition occurs in approximately 1% of singleton pregnancies but is more common in multiple gestations. Associated risks include vasa previa (when vessels cross the internal cervical os), fetal growth restriction, preterm labor, and emergency cesarean delivery due to fetal distress. Diagnosis is typically made by ultrasound examination of cord insertion site during routine anatomic survey.
Usage
Usage note: Velamentous derives from velamen (veil). Often associated with vasa previa when vessels cross internal os.
In Context
- "Ultrasound revealed velamentous cord insertion with vessels running through the membranes near the cervix." — Anatomy scan report
- "The velamentous cord insertion was associated with asymmetric fetal growth restriction." — Maternal fetal medicine consultation