Don't Say "A Downs Baby"
A person with Down syndrome is not the disability. There are many other things that should, and do, define a person. It is dehumanizing and strips people of dignity when they are referred to as their disability. Instead of saying “he is a Downs baby” or “she is Downs” try “he/she has Down syndrome.” 
Don't Say "Down Syndrome Child/Baby/Person"
Refer to the person first, not the disability. This is one of the most common misstatements made and often causes parents to cringe, at least inwardly. For example, we don’t say “a diabetes child” or “an asthma person,” so eliminating this reference is critical. Instead use “a child with Down syndrome” – “an individual with Down syndrome.” 
Don't Say "They're Not Normal"
Please realize that we perceive our kids as being pretty normal kids. Comparing them to your version of "normal" children implies that a child with Down syndrome is something less than normal. 
Don't Say "Retard/Retarded"
Currently, the best reference is developmentally delayed (for children) and developmentally disabled (for adults). The “R” word is not acceptable. 
Don't Say "Mongoloid"
This is an extremely outdated term that was once used to refer to people with Down syndrome. The word should never be used when referring to or about someone with Down syndrome. 
Don't Say "Handicapped"
 Use “has a disability or a differing ability." 
Don't Say "Suffers From/Afflicted With Down Syndrome"
Individuals with Down syndrome are not suffering or afflicted. We must instill a great sense of pride and self-esteem in all children, so our language must show that Down syndrome is not terrible, or anything to be ashamed about. 
Don't Say "Downs Syndrome"
There is no “s” in Down syndrome and the word “syndrome” is not capitalized.