Head Circumference Charts for Children with Down Syndrome

You may be wondering (as I did) why we only have charts for children from birth to three years of age.  I asked Dr. Len Leshin about this and he said, "Pediatricians stop measuring head circumferences of all children at about three years of age.  That's because if there's a problem with microcephaly or hydrocephalus, we'll find it by then."
Girls (birth-3)
Boys (birth-3)
Head Circumference Chart (cm) Head Circumference Chart (cm) 
Each head circumference chart shows three curves labelled +2 Std Dev, 50th Percentile, and -2 Std Dev.
The 50th Percentile curve represents the average head circumference growth for children with Down syndrome. 95% of children with Down syndrome will fall between the lower curve (-2 Std. Dev.) and the upper curve (+2 Std. Dev.).

Interpretation:  If your child's head circumference falls between the lower and upper curves and follows along the path of the curves on the chart, that is an indication of normal head growth.  If you have questions or concerns about your child's head circumference, you should consult your child's pediatrician.

Reference:  Palmer, et al. (1992). Head circumference of children with Down syndrome (0-36 months).  American Journal of Medical Genetics, 42, 61-67.

Method:  I superimposed a grid on the charts and then recorded the 37 points where each curve intersects the age in months on the x-axis.  I entered the data in a spreadsheet and graphed the results.  If you have English measurements, use the following conversion factor:

To convert inches to centimeters:   cm  =  inches  x  2.54

If you have comments or suggestions about improving these charts, please email me.

Greg Richards

Return to the Growth Charts Home Page

Revised: August 17, 1999