Fig. 29.3. Estimates of insertion length of umbilical catheters

(umbilical artery catheter tip inserted between T6 and T10;

umbilical vein catheter tip inserted above diaphragm in inferior

vena cava near right atrium) based on birthweight (BW) (with

95% confidence intervals). Modified estimating equations utilizing BW are as follows: umbilical artery length = 2.5 BW + 9.7

(top) and umbilical vein length = 1.5 BW + 5.6 (bottom), where

BW is measured in kilograms and lengths are measured in centimeters. (From Shukla H, Ferrara A. Rapid estimation of insertional length of umbilical catheters in newborns. Am J Dis Child.

1986;140:787, with permission.)

Fig. 29.4. Anatomic relations of the umbilical arteries, showing relationships with major arteries supplying

buttocks and lower limb.