Figure 3.

Linear correlation (r = correlation coefficient of Spearman) of the inter-observer ultra-sonographic measurements: A. of the diameter of the umbilical cord (cord₁ and cord₂ are respectively the measurements of observer 1 and 2); and B. of the cross-sectional area of the umbilical cord (area₁ and area₂ are respectively the measurements of observer 1 and 2).