During a follow-up for an infant with a history of surgery, which assessment finding is significant?

The assessment finding of bulging fontanels is significant in an infant, particularly after a history of surgery. Bulging fontanels can indicate increased intracranial pressure, which may arise due to complications such as bleeding, infection, or other issues related to the surgical procedure. The fontanels, or soft spots on an infant's skull, serve as an important indicator of intracranial health; thus, any abnormality such as bulging warrants further investigation and swift medical intervention.

In comparison, decreased appetite and sporadic weight gain might suggest feeding issues but do not have the same immediate implications for the child's neurological status. Normal range of motion and muscle tone can indicate adequate physical development, while the presence of infantile reflexes, although part of typical neurological development, does not imply any acute problem and is expected in an infant of that age. Therefore, among the assessment findings presented, bulging fontanels is particularly concerning and signifies the need for immediate evaluation.