Final answer:
Excessive traction on the cord during the 3rd stage of labor can cause severe complications, including umbilical cord prolapse, reduced oxygen supply to the baby, and potential brain damage or stillbirth.
Step-by-step explanation:
Excessive traction on the cord during the 3rd stage of labor can cause severe complications. It can lead to umbilical cord prolapse, which occurs when the cord slips through the open cervix and becomes compressed between the baby's head and the birth canal. This can reduce or cut off the baby's oxygen supply and may result in brain damage or stillbirth. It is important for healthcare professionals to carefully manage the delivery process to prevent excessive traction on the cord and ensure the safety of both the mother and the baby.