Recurrence of Down Syndrome

What is the risk that parents of a child with Down syndrome will have another affected child?

In general, in each subsequent pregnancy, the chance of having another baby with Down syndrome is 1 percent plus whatever additional risk a mother has, based upon her age. If, however, the first child has translocation Down syndrome, the chance of having another child with Down syndrome may be greatly increased.  

After birth, the provider takes a blood sample from a baby suspected of having Down syndrome and sends it to a laboratory. The lab examines the chromosomes (called a karyotype) to determine if the baby has Down syndrome and what genetic form of Down syndrome the baby has. This information is important in determining the risk in future pregnancies. The doctor may refer parents to a genetic counselor who can explain the results of chromosomal tests in detail, including what the recurrence risks may be in another pregnancy.

Also see Dr. Len Leshin's web-site for more information.