Figure 4From: Inter- and intra-observer variability in Sonographic measurements of the cross-sectional diameters and area of the umbilical cord and its vessels during pregnancy Linear correlation (r = correlation coefficient of Spearman) of the intra-observer ultrasonographic measurements: A. of the diameter of the umbilical cord (cord1 and cord3 are respectively the first and second measurements of observer 1); and B. of the cross-sectional area of the umbilical cord (area1 and area3 are respectively the first and second measurements of observer 1).Back to article page