Fontanel
The soft spots on an infant's skull where cranial bones have not yet fused
Definition
Fontanels are the soft, membranous gaps between the cranial bones of an infant's skull that allow for brain growth and passage through the birth canal.
Types and Closure
- Anterior fontanel (diamond-shaped): Closes at 12 to 18 months.
- Posterior fontanel (triangular): Closes by 2 to 3 months.
Clinical Assessment
Palpate gently. Normal: Flat, soft, may pulsate with heartbeat.
Abnormal Findings
- Sunken fontanel: Dehydration, malnutrition.
- Bulging fontanel: Increased intracranial pressure, such as meningitis, hydrocephalus, intracranial hemorrhage. EMERGENCY.
- Delayed closure: Hypothyroidism, rickets, Down syndrome, increased ICP.
- Premature closure (craniosynostosis): Abnormal head shape.
Nursing Considerations
Assess with infant calm and upright when possible (crying can cause bulging). Note shape, size, and tension. Measure head circumference at each well-check.
NCLEX Relevance
Sunken = dehydration. Bulging = increased ICP.