A nurse is assessing the fontanels of an 8-month-old infant. Which of the following findings should the nurse recognize as an expected finding
A.
The anterior fontanel is open.
B.
Both fontanels are the same size.
C.
The posterior fontanel is open.
D.
Both fontanels show moulding
The Correct Answer and Explanation is:
The correct answer is B. Both fontanels are the same size.
Explanation:
Fontanels are the soft spots on an infant’s skull where the bones have not yet fused. They are important indicators of an infant’s growth and development and can provide valuable information about intracranial pressure and overall health.
- Anterior Fontanel:
- The anterior fontanel is located at the top of the infant’s head, where the frontal and parietal bones meet. It is typically diamond-shaped and is larger than the posterior fontanel.
- By 8 months of age, the anterior fontanel should be slightly open but is expected to be smaller than at birth. It usually closes by 12-18 months of age.
- Posterior Fontanel:
- The posterior fontanel is located at the back of the infant’s head, where the parietal bones meet the occipital bone. It is triangular and smaller than the anterior fontanel.
- By 8 months of age, the posterior fontanel should be closed or nearly closed. It generally closes by 2-3 months of age.
Analysis of Options:
- A. The anterior fontanel is open.
- At 8 months, the anterior fontanel should still be open, but it should be much smaller than at birth. An open anterior fontanel is expected, but if it is abnormally large, it may indicate conditions such as increased intracranial pressure.
- B. Both fontanels are the same size.
- This is the expected finding. While the anterior fontanel is larger than the posterior fontanel, by 8 months, both fontanels should be proportionate in size to each other, with the posterior fontanel being smaller and likely closed, and the anterior fontanel being open but reducing in size.
- C. The posterior fontanel is open.
- By 8 months, the posterior fontanel is expected to be closed or nearly closed. If it is open, it could indicate potential issues such as developmental delays or other abnormalities.
- D. Both fontanels show moulding.
- Moulding refers to the shaping of the infant’s head due to pressure during delivery. By 8 months, moulding should not be evident as the head shape should have returned to normal post-delivery. Any residual moulding is not an expected finding at this age.
Thus, the correct answer is B. Both fontanels are the same size, reflecting a typical and expected developmental pattern for an 8-month-old infant.