A labor and delivery nurse is assessing a newborn baby boy. Which finding would indicate possible microcephaly?

  1. depressed fontanelles during feeding
  2. hypoactivity
  3. head circumference in lowest tenth percentile
  4. absent fontanelles
Number 3 is correct.
Rationale: A baby with microcephaly typically has a head circumference in the lowest tenth percentile. Other signs and symptoms may include facial distortions, dwarfism, and seizures. Hyperactivity, not hypoactivity, is a symptom of microcephaly. Depressed fontanelles could indicate a nutritional problem or dehydration in the infant. Absent fontanelles might be a sign of other medical conditions, such as craniosynostosis.