Microcephaly



	Microcephaly is a head size (measured as the distance around the top of the head) significantly below the median for the infant's age and sex. Significantly below is generally considered to be smaller than 3 standard deviations below the mean, or less than 42 cm in circumference at full growth. It most often occurs because of failure of the brain to grow at a normal rate.

Review Date: 11/13/2011
Reviewed By: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine; Neil K. Kaneshiro, MD, MHA, Clinical Assistant Professor of Pediatrics, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.

The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. © 1997- A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.