Diagnosing Down Syndrome

Since many expectant parents choose to forgo prenatal tests, most cases of Down syndrome are diagnosed after the baby is born. Doctors will usually suspect Down syndrome if certain physical characteristics are present.

SOME OF THE TRAITS COMMON TO BABIES WITH DOWN SYNDROME INCLUDE

  • Low muscle tone
  • A flat facial profile
  • A small nose
  • An upward slant to the eyes
  • A single deep crease across the center of the palm
  • An excessive ability to extend the joints
  • Small skin folds on the inner corner of the eyes
  • Excessive space between large and second toe

Not all babies with Down syndrome have all these characteristics, and many of these features can be found, to some extent, in individuals who do not have the condition. Therefore, doctors must perform a special test called a karyotype before making a definitive diagnosis.  To obtain a karyotype, doctors draw a blood sample to examine your baby’s cells. They photograph the chromosomes and then group them by size, number and shape. By examining the karyotype, they can determine accurately whether or not your baby has Down syndrome.