From the Research
No, it is not normal for a baby's anterior fontanelle to close before 6 months of age. The anterior fontanelle typically remains open until 9-18 months of age, with an average closure time around 12-14 months. Early closure before 6 months is concerning and warrants immediate medical evaluation by a pediatrician. This condition, called craniosynostosis, occurs when the skull bones fuse prematurely and can restrict normal brain growth and development. According to a study published in 2024 1, fontanellar bone, an exceedingly rare ossification anomaly of the anterior fontanelle, clinically mimics craniosynostosis. However, another study published in 2021 2 suggests that most cases of "early" or "late" closure of the anterior fontanelle are benign variations.
Key Points to Consider
- The anterior fontanelle serves an important purpose during birth by allowing the skull bones to overlap as the baby passes through the birth canal, and after birth by accommodating rapid brain growth during the first year of life.
- Signs that may accompany early fontanelle closure include an abnormal head shape, increased irritability, poor feeding, vomiting, or developmental delays.
- Early diagnosis is crucial because treatment often involves surgical intervention to allow proper brain growth.
- A study published in 2014 3 provides reference charts detailing anterior fontanelle closure frequency and surface area as a function of age, suggesting that early or delayed closure may represent normal variants.
Recommendation
Parents should promptly consult their child's doctor if they notice the soft spot has disappeared earlier than expected, as early evaluation and diagnosis are essential for proper management and treatment. It is also important to note that while some cases of early closure may be benign, it is always best to err on the side of caution and seek medical evaluation to rule out any potential underlying conditions.