What is the average diameter of a normal umbilical cord?

The average diameter of a normal umbilical cord typically ranges around 1.5 cm. This measurement can vary somewhat among neonates, but 1.5 cm is widely accepted as the average size in a healthy term infant. The umbilical cord plays a vital role in fetal development by facilitating the exchange of nutrients, gases, and waste products between the mother and the fetus, and its optimal dimensions are important for ensuring adequate blood flow and function throughout gestation.

In comparison to the other provided options, 1 cm, 2 cm, and 3 cm are either too small or too large to be consistent with typical observations in clinical practice. A cord measuring 1 cm may be indicative of a pathological condition, while diameters of 2 cm or 3 cm could suggest an abnormality such as cord thickening or other associated complications. Thus, the choice of 1.5 cm aligns best with established medical literature and reflects standard clinical understanding.