Final answer:
Clamping the umbilical cord affects the heart rate of the newborn, causing a decrease and triggering the baby to take its first breath.
Step-by-step explanation:
Clamping the umbilical cord affects the heart rate of the newborn. When the cord is clamped, the baby can no longer receive oxygenated blood from the mother through the placenta, causing a decrease in heart rate. This triggers the baby to take its first breath and initiate the major circulatory reconfiguration.