Which statement by the parents of a newborn after circumcision indicates understanding of care instructions?

The statement about applying petroleum jelly to the penis with each diaper change demonstrates an understanding of proper care after circumcision. This practice helps to keep the surgical site moist, which can aid in healing and prevent the diaper from sticking to the area, thereby minimizing discomfort for the newborn. Applying petroleum jelly can also protect the area from irritation caused by urine and feces.

In the context of the other statements, cleaning the area with alcohol wipes is not recommended because it can cause irritation to the delicate healing tissue. Avoiding touching the area is overly restrictive; care must include gentle cleaning and inspection to ensure proper healing. Using baby powder could be inappropriate as it might irritate the area or be harmful if inhaled. Therefore, the use of petroleum jelly aligns with recommended care practices post-circumcision.