When assessing the fontanels of a 6-month-old infant, which of the following findings would be expected?

Assessment of infant fontanels provides important information about skull development, hydration status, and intracranial pressure. In a 6-month-old infant, normal skull ossification is still in progress, allowing flexibility for brain growth. The anterior fontanel typically remains open during the first year of life, while the posterior fontanel closes much earlier. Recognizing expected closure timelines helps differentiate normal development from potential abnormalities. A. Both anterior and posterior fontanels being closed is not expected at 6 months. While the posterior fontanel usually closes by 2–3 months of age, the anterior fontanel remains open much longer, typically until 12–18 months. Early closure of the anterior fontanel may indicate conditions such as craniosynostosis, which can impair brain growth. B. Bulging of both fontanels is an abnormal finding and may indicate increased intracranial pressure, infection such as meningitis, or hydrocephalus. Fontanels should be soft and flat under normal conditions. Persistent bulging, especially when the infant is calm and upright, requires immediate medical evaluation. C. The anterior fontanel being open is the expected finding in a 6-month-old infant. It allows for continued brain growth and skull expansion during infancy. The fontanel should feel soft and slightly concave or flat, indicating normal hydration and intracranial pressure. D. The posterior fontanel is typically closed by 2–3 months of age, making it unlikely to be open at 6 months. Persistence of an open posterior fontanel beyond this period may suggest delayed ossification or underlying conditions such as hypothyroidism or increased intracranial pressure.