A full-term infant with a head circumference of 39 cm is diagnosed with?

A head circumference of 39 cm in a full-term infant falls within the category of macrocephaly. Macrocephaly is defined as an abnormally large head size that exceeds the standard deviation for a given age and sex. In newborns and infants, a head circumference above the 95th percentile is typically considered macrocephaly.

It is important to consider growth norms and percentiles when assessing an infant's head circumference. For full-term infants, a head circumference around the mean can vary slightly, but anything significantly larger indicates a potential concern that requires monitoring or further evaluation. This understanding is critical in neonatal and pediatric transport, where close attention to development and potential abnormalities is essential for appropriate interventions and care.

The other options relate to conditions defined by head size but do not accurately apply in this scenario; microcephaly would imply an abnormally small head, normocephaly refers to a head size that is within normal limits, and hydrocephalus specifically indicates the accumulation of cerebrospinal fluid in the brain, which may lead to an enlarged head but is a clinical diagnosis rather than a mere measurement assessment. Thus, the diagnosis of macrocephaly aligns with the provided measurements and definitions in the context of a