Objective:

Determine the blood content of the post-birth umbilical cord and its relation to size and cut-off time as well as analyze the possible clinical implications.

Material and methods:

The amount of residual blood in the umbilical cord of 252 infants was used to estimate confidence intervals of the mean blood content of the post-birth umbilical cord in relation to gestational age, cord length and cut time.

Results:

The average blood content in the cord was 1.2 mL/kg/weight or 0.19 mL/cm in the 252 patients. In cords that are greater than 25 cm long we find 2.29 mL/kg and in those less than 25 cm long we find 0.79 mL/kg. When using late clamping we obtained 2.27 mL/kg and with an early cut 2.34 mL/kg. In premature infants, the amount of blood with cord length < 25 cm was 0.89 mL/kg and with cord length > 25 cm of 3.09 mL/kg although there were only five children in this group. In the case of full-term births with cord length < 25 cm, the amount of blood was 0.78 mL/kg and 2.22 mL/kg for the case of cord length > 25 cm.

Conclusions:

The umbilical cord with a length greater than 25 cm can provide a transfusion of 2.29 mL/kg, cord clamping time has little impact on the blood total amount obtained.