Final answer:
The procedure to clamp and cut the umbilical cord involves clearing the newborn's airways, double-clamping the cord, and cutting between the clamps. The vessels within the cord collapse, naturally closing off within 20 minutes if left unattended, but immediate clamping ensures a safe and clean process.
Step-by-step explanation:
Upon the birth of a newborn, the obstetrician will immediately take steps to ensure the baby's airways are clear by aspirating mucus from the mouth and nose. The baby's first breath should occur within 10 seconds of birth. Following this, the umbilical cord is double-clamped with medical clamps and then cut between the two clamps. This action separates the newborn from the placenta and marks the completion of the second stage of childbirth. Subsequent to the cutting, the umbilical cord's blood vessels collapse and naturally close off, which would occur even without medical intervention within 20 minutes due to the Wharton's jelly swelling in response to lower external temperatures.
This procedure causes the three umbilical blood vessels to collapse, which had served as vital conduits during fetal development, transporting oxygenated blood and nutrients to the fetus from the placenta. After the cord is cut, the circulatory adjustments take place; the ductus venosus becomes the ligamentum venosum, and the Wharton's jelly within the umbilical cord helps to close off the umbilical vessels as it swells. In the absence of medical clamping, the natural occlusion of the umbilical cord occurs when it stops pulsating, indicating the closure of the blood vessels. Nevertheless, immediate medical clamping is practiced to ensure a controlled and sanitary separation of the neonate from the placenta.