What will the nurse expect when assessing the anterior fontanelle of a healthy, full-term newborn?

A. Smaller than the posterior fontanelle: The anterior fontanelle is larger than the posterior fontanelle. The anterior fontanelle is typically 2.5 to 4 cm in diameter, while the posterior fontanelle is much smaller, measuring about 0.5 to 1 cm. B. Triangular shaped: The triangular shape is characteristic of the posterior fontanelle, not the anterior fontanelle. C. Open and diamond shaped: The anterior fontanelle is normally open at birth and diamond-shaped. It allows for skull flexibility during birth and typically closes between 12 and 18 months of age, indicating normal development. D. Depressed and sunken: A sunken fontanelle may indicate dehydration or fluid loss. In a healthy full-term newborn, the anterior fontanelle should be flat or slightly concave but not markedly depressed.