Final answer:
The ideal time to clamp the umbilical cord is usually between 1 to 3 minutes after birth to allow blood transfer from the placenta, although traditionally it was done within seconds. Delayed clamping may offer health benefits such as increased iron levels. Naturally, the umbilical cord would constrict and stop pulsating within about 20 minutes after birth without medical intervention.
Step-by-step explanation:
The ideal time to clamp the umbilical cord is a topic of ongoing research and debate. Traditionally, the umbilical cord has been clamped within seconds after birth. However, the World Health Organization and other health bodies have recommended delayed clamping, generally from 1 to 3 minutes after birth, to ensure that the newborn receives a greater amount of blood from the placenta, which can provide benefits such as increased iron stores and reduced risk of anemia. Once the baby takes its first breath, a significant circulatory reconfiguration takes place; pulmonary alveoli open, pulmonary resistance decreases, and the lungs begin respiration, taking over the vital role formerly managed by the placenta. After aspiration of mucus from the newborn's mouth and nose by the obstetrician, the umbilical cord is double-clamped and cut.
Without medical intervention, the occlusion of the umbilical cord would naturally occur within about 20 minutes as the Wharton's jelly in the umbilical cord responds to the cooler external temperature and the blood vessels constrict. The umbilical cord stops pulsating once this natural occlusion has taken place. Subsequently, the vessels become fibrotic remnants within the mature circulatory system. After the umbilical cord is cut, leaving a short stub, the stub dries and eventually forms the navel as it detaches a few weeks after birth.