Antenatal umbilical coiling index and Doppler flow characteristics

Area of Science:

• Perinatology
• Fetal Medicine
• Medical Imaging

Background:

• The umbilical cord's structure, including coiling, is crucial for fetal development.
• Variations in umbilical cord coiling may influence fetal well-being and placental function.

Purpose of the Study:

• To investigate the association between antenatal umbilical coiling index (UCI) and umbilical cord Doppler flow parameters.
• To determine if umbilical cord coiling patterns correlate with fetal blood flow characteristics.

Main Methods:

• Prospective study of 200 pregnant patients at 18-23 weeks' gestation.
• Umbilical coiling patterns and Doppler flow (umbilical vein flow, umbilical artery resistance index [RI], peak systolic velocity [PSV]) were assessed.
• Antenatal umbilical coiling index (UCI) calculated as reciprocal of inter-coil distance.

Main Results:

• 154 patients included; mean antenatal UCI was 0.40.
• Significant correlations found between antenatal UCI and umbilical artery RI, PSV, and umbilical vein blood flow volume.
• Lower RI and higher PSV/umbilical vein flow associated with higher antenatal UCI (P=0.016, P<0.001, P=0.032).
• Only PSV showed significant differences when stratified into hypo-, normo-, and hypercoiled groups (P=0.016).

Conclusions:

• Umbilical cord coiling appears to modulate umbilical cord blood flow.
• Increased coiling (higher UCI) may protect blood flow by decreasing resistance and increasing velocity/volume.
• Clinical implications are uncertain due to lack of significant Doppler differences across stratified coiling groups.