Final answer:
For most healthy newborns, delayed umbilical cord clamping for at least 1-3 minutes is recommended to allow transfer of additional blood from the placenta to the infant.
Step-by-step explanation:
In the case of most vigorous newborns who do not require resuscitation, the recommended practice is to delay the clamping of the umbilical cord. Delayed umbilical cord clamping allows additional blood from the placenta to transfer to the infant, providing extra iron and reducing the risk of iron deficiency. This practice is often recommended for at least 1-3 minutes following birth, aligning with World Health Organization guidelines, unless there is a medical indication to clamp sooner. The process of naturally occluding the blood vessels of the umbilical cord, in the absence of medical intervention, occurs within approximately 20 minutes due to the constriction of blood vessels as the Wharton's jelly swells in response to the colder external temperature.
Immediately after birth, the umbilical cord, which contains an umbilical artery and vein, is double-clamped and then cut. The remaining stump will dry out and eventually form the navel. However, the practice of delayed umbilical cord clamping takes advantage of the time it takes for the natural occlusion to occur, benefiting the newborn's circulatory adjustments as the lungs take over the duties of the placenta.