Skip to main content
Intermediate Technical IVT

microcephaly

Pronunciation: mahy-kroh-SEF-uh-lee

A condition where a baby's head circumference is significantly smaller than expected for age and sex.

Full Definition

Microcephaly is defined as a head circumference more than two standard deviations below the mean for age, sex, and ethnicity. This condition can be congenital (present at birth) or acquired (developing after birth due to injury, infection, or other causes). In pediatric neurology, microcephaly often indicates abnormal brain development and may be associated with intellectual disability, seizures, developmental delays, and various genetic syndromes. The condition can be isolated or part of a broader syndrome requiring comprehensive neurological evaluation.

Usage

Usage note: Always specify measurement in standard deviations below mean and distinguish from normal variant small head size.

In Context

  • "Serial head circumference measurements confirmed progressive microcephaly in the 6-month-old patient." — Pediatric neurology follow-up note

Also known as

small head circumference

Contrasted with

macrocephaly

Don't confuse with

craniosynostosis failure to thrive

Editors from these organisations have used our services since 1998

Reuters BBC Oxford University Press Penguin Random House Springer Microsoft Suncor Energy United Nations Fisher Investments IBM The Home Depot KODAK CHEVRON