Final answer:
Puncturing an infant's foot deeper than 2.5mm can damage structures such as bones or blood vessels leading to complications like infection or impaired growth.
Step-by-step explanation:
If you puncture an infant's foot deeper than 2.5mm, there is a risk of damaging deeper structures within the foot such as bones, tendons, or blood vessels. Such a deep puncture can lead to complications like infection, bleeding, and interference with bone growth or development. In infants, the heel is a common site for blood sampling, thus the recommended depth for heel should not exceed 2.0mm in preterm infants and 2.5mm in term infants to avoid such risks.