A nurse is assessing an infant during a routine health examination. The nurse notes that the infant's anterior fontanel is sunken. How should the nurse interpret this finding?

Rationale: A. A sunken anterior fontanel is not an expected finding in healthy infants. Normally, the anterior fontanel is level with the surrounding skull and may pulsate slightly with the heartbeat. B. Increased intracranial pressure typically causes the fontanel to bulge, not sink. A bulging fontanel may indicate conditions such as hydrocephalus, meningitis, or intracranial hemorrhage. C. While the fontanel allows for brain growth and skull expansion, a sunken fontanel does not indicate normal brain development. Normal development is reflected by a soft, flat, and appropriately sized fontanel. D. A sunken anterior fontanel is a classic sign of dehydration in infants. Dehydration reduces the volume of intracranial fluid and tissues, causing the soft spot to appear concave. Other signs of dehydration may include dry mucous membranes, decreased urine output, lethargy, and poor skin turgor.