Final answer:
Effective teaching is demonstrated when the new mother knows to contact her physician if there is a white or yellow discharge from the baby's umbilical cord, which could signal an infection.
Step-by-step explanation:
The nurse determines the teaching is effective if the new mother indicates that she will contact her physician if there is a white or yellow discharge from the cord. This is because such a discharge can be indicative of an infection. After the umbilical cord is cut at birth, leaving a stub, it will dry out, darken, and fall off within about three weeks to form the navel once fully healed. It is essential to keep the area around the umbilical cord clean and dry until it falls off to prevent infection. The diaper should be folded down away from the cord to keep the area dry and exposed to air. Also, until the umbilical cord falls off, sponge baths are recommended to avoid submerging the cord in water.