Cord centrality and eccentricity indices of the placenta and their associations
Narayanan, S.; Mohamed, T.; Shankar, N.
Abstract
Introduction: The shape of the placenta and position of umbilical cord insertion are associated with perinatal outcome. Cord centrality index (CCI) is a measure of the distance of the umbilical cord insertion from the center of the placenta. Eccentricity index (EI) is a measure of placental shape. Hyrtl’s anastomosis (HA) connects the two umbilical arteries and helps to equalize pressure differences. The hypothesis of the study was that there would be a significant correlation between the diameter of HA and the CCI and EI. Materials and Methods: The maximum length, maximum breadth, and distance of the umbilical cord insertion from the center were estimated using Image J software on superior view digital photographs of 88 placentae. The CCI and EI were then calculated. Relevant diameters were measured, and the twist of each umbilical cord was categorized as left and right. Strength of association was estimated using Spearman’s correlation, and the independent sample T test for estimating group differences. Results: The mean values of the CCI and EI were 0.41±0.19 and 0.42±0.17. A significant correlation was noted with the diameter of HA between both CCI (0.237, p = 0.029) and EI (–0.252, p = 0.020). No significant differences were observed in the CCI and EI between cords with right and left twist. Conclusion: A greater diameter of the HA is likely be indicative of a higher difference in the blood flow between the umbilical arteries which in turn could influence the placental shape and umbilical cord insertion.