Question
Why do some babies close their fontanels later?
Answer
Under normal circumstances, a newborn’s posterior fontanel may be small or already closed at birth, while the anterior fontanel is about 1.5 to 2.5 centimeters in diagonal at birth. The posterior fontanel usually closes by 6 to 8 weeks after birth, and the anterior fontanel typically closes between 1 and 1.5 years of age. If the fontanel closure is delayed, it may be related to calcium deficiency and hypothyroidism. In some cases, a delayed closure of the anterior fontanel may be due to increased intracranial pressure caused by hydrocephalus or other reasons. In such situations, it is recommended to visit the hospital for further examination.