What is a furcate cord insertion and what is its clinical significance?

Furcate Cord Insertion: Definition and Clinical Significance

Furcate cord insertion is a rare umbilical cord abnormality where the umbilical vessels branch and separate from the cord substance before reaching the placental surface, leaving the vessels unprotected by Wharton's jelly and vulnerable to rupture, hemorrhage, and fetal death. 1, 2

Definition and Anatomical Features

Furcate insertion differs from normal cord insertion in that the umbilical vessels divide prior to contacting the placenta, creating exposed fetal vessels without the protective covering of Wharton's jelly 2, 3. This branching pattern leaves the vessels mechanically vulnerable at the insertion site 1.

Clinical Significance and Risks

Immediate Life-Threatening Complications

• Vessel rupture and fetal hemorrhage can occur spontaneously during labor or delivery, requiring emergent neonatal resuscitation and blood transfusion 1
• Sudden intrauterine fetal death from hemorrhage at the furcate insertion site is a documented complication 2, 4
• Cord avulsion during delivery has been reported, leading to acute fetal blood loss 1

Associated Pathological Changes

• The placental tissue beneath the furcate insertion often shows fibrin deposition, focal infarction, and deficient parenchymal tissue replaced by white, elastic hard tissue 2
• Fatal complications from abnormal cord insertions account for 7.7-11.4% of all stillbirths 4

Associated Fetal Anomalies

• Furcate insertion may occur with congenital anomalies such as VACTERL association 3
• Duplex placenta has been reported in conjunction with furcate insertion 3

Prenatal Diagnosis

Detailed color Doppler ultrasound during the second-trimester anatomy scan (18-22 weeks) can identify furcate insertion by demonstrating umbilical vessels separating from the cord substance before placental insertion. 2, 5

Diagnostic Approach

• Systematic evaluation of cord insertion should be performed at the routine anatomy scan using transabdominal ultrasound with color Doppler 6
• When furcate insertion is suspected, transvaginal ultrasound with color Doppler provides superior visualization 6
• The diagnosis is confirmed by visualizing the umbilical vessels branching away from the cord before reaching the placental surface 2, 5

Management Recommendations

Surveillance Protocol

• Serial ultrasound surveillance throughout pregnancy focusing on fetal growth, amniotic fluid assessment, and umbilical artery Doppler velocimetry is essential once furcate insertion is diagnosed 6
• Fetal biometry should be performed every 2-3 weeks to monitor for growth restriction 6
• Umbilical artery Doppler assessment should be performed when growth restriction is suspected 6

Delivery Planning

• Labor induction at term (37 weeks) with close intrapartum monitoring is recommended to allow for immediate intervention if vessel rupture occurs 5
• Cesarean delivery should be strongly considered if furcate insertion is combined with fetal growth restriction and abnormal Doppler findings 7
• Avoid digital pelvic examination without first confirming the exact location of the vessels to prevent triggering vessel rupture 8

Critical Pitfalls to Avoid

• Most cases remain prenatally undiagnosed, leading to unanticipated complications during delivery 1
• Difficulty with placental extraction may occur, potentially requiring postpartum dilation and curettage 3
• The rarity of this condition means many clinicians lack awareness of its potentially lethal complications 1, 2

Key Distinction from Velamentous Insertion

While furcate insertion involves vessel branching before placental contact, velamentous cord insertion involves vessels inserting into the membranes rather than the placenta 8. Both conditions leave vessels unprotected, but furcate insertion specifically involves branching at the placental surface 2. The two conditions may coexist, creating compounded risk 5.