Coiling Index of umbilical vessels-Its relevance

Umbilical Cord Coiling (UCI  ) : Ans: It is a ratio between the number of complete coils divided by the length of the cord in centimeters.  Sonological  assessment of  the umbilical cord  can reveal the direction  of cord twists and the frequency of twists of the vessels   . The normal umbilical cord coiling index is calculated as the number of complete coils divided by the length of the cord in centimeters.    In a study long back,   the mean  UCI  was 0.17 in uncomplicated pregnancies and those researchers  have reported the frequency  of  coils and outcome of fetus . Therefore there is a clinical correlation with abnormal   coiled cords.  Abnormal cord coiling has been  associated with adverse  pregnancy   outcome. Antenatal detection of abnormal   cord coil index by USG can be performed. The antenatal UCI can be calculated by measuring   the distance   between two pairs of coils as  seen on longitudinal US images  of the umbilical  cord. The sonographic evaluation of umbilical cord coiling in the second trimester was found to correlate with true  UCI obtained after   birth    . In one series abnormal cord   coiling detected at second trimester USG was associated with a  higher prevalence of SGA  neonates  and CTG with nonreassuring fetal   status  in labor   . Such investigations however admitted that UCI should not be an isolated indication of elective CS unless this is associated with CTG changes or SGA. The cord  coil  index  the reliability  of its detection by US in utero  and the  impact on clinical   outcome  warrants  further  study  and is under investigation.