Final answer:
When the umbilical cord is wrapped around the newborn's neck, the medical provider should try to loosen and slip it over the baby's head or, if too tight, clamp and cut it to prevent blood flow restriction before the rest of the newborn is delivered. After birth, the cord is double-clamped and cut to ensure the baby's independent breathing. The remaining cord dries out, forming the navel.
Step-by-step explanation:
Upon the delivery of an infant's head, if the umbilical cord is wrapped around its neck, which is a condition known as nuchal cord, immediate action is required due to the risk it poses. The appropriate step is to attempt to gently slide the cord over the baby's head if there is enough slack. If the cord is too tight to be moved over the head safely, the attending obstetrician or midwife may have to carefully clamp and cut the cord to release it before the body of the newborn is delivered. This approach minimizes the risk of restricting the blood flow to the baby, which the umbilical cord provides through its two arteries and one vein. After the newborn is fully delivered, the umbilical cord is usually double-clamped, and a cut is made between the clamps which initiates the infant's independent circulation, since they must begin breathing on their own and can no longer rely on the placenta for the elimination of carbon dioxide and intake of oxygen.
The double clamping and cutting process collapses the umbilical blood vessels, and in the absence of medical assistance, the occlusion would naturally occur as the Wharton's jelly within the umbilical cord swells in response to the cooler external temperature, causing blood vessels to constrict. The remaining part of the umbilical cord attached to the infant will then dry out, shrivel, and eventually become the navel as it falls off within about three weeks of birth.