Can the difference of Doppler indexes at the different points of the umbilical artery predict to the umbilical cord length?

The aim of the study is to investigate whether the Doppler indexes which measured at different points of the umbilical cord (UC) are related to the cord length. In this prospective study, umbilical artery (UA) Doppler indexes were measured at the fetal and placental insertion, free loop (FL) and intra-abdominal (IA) portion at 37-42 weeks of gestation in low-risk singleton pregnancies. After birth, the UC was measured. The difference of Doppler indexes of different points was evaluated by nonparametric Kruskal-Wallis test or analysis of variance (ANOVA) test and significant values have been adjusted by the Bonferroni correction for multiply tests. The correlation of between UC length and change of Doppler indexes which measured at different points of the UC was evaluated using Spearman's rank correlation test. The data of 74 participants were analyzed in this study. Mean UC length was 58 cm (min: 38 cm and max: 84 cm). There was no difference between characteristics of two groups that UC length <58 cm and ≥58 cm and different percentiles. UA systole/diastole (S/D) rate, resistance index (RI), and pulsatility index (PI) were higher at the IA portion than other measurement points ( = .003, <.001, and <.001, respectively). The mean differences (delta values) of UA blood velocity between the fetal and placental ends (PEs) were correlated UC length ( = 0.32,  = .04). The differences of UA blood velocities between the fetal and PEs may be a useful marker for UC length prediction during antenatal period.