Developmental Scale for Children with Down Syndrome

Editor’s note: The accompanying form can be downloaded via the link at the bottom of this post.

Social and Communication Issues

One of the most frequently asked questions by parents of children with Down syndrome is how their child is doing compared to other children with Down syndrome?  They are curious as to whether their child is keeping up with typically developing children, but realize that it is more important to judge their child with other children with a similar syndrome.  To assist in the answer to this question, I have developed a Developmental Scale for Children with Down Syndrome.  The Developmental Scale provides the best information I know about young children with Down syndrome seen in our clinic as well as what we have read in the literature.  It also provides what typically developing children demonstrate during infancy, toddler, and preschool ages.  The Developmental Scale has not been scrutinized by colleagues or parents, and, therefore, provides only our best judgment of what can be expected.
It is important to point out that all children, even typically developing children, do not look alike.  Each child is different and progresses at his or her own rate: each presents with particular strengths and demonstrates inherited weaknesses.  This, of course, is the same for children with Down syndrome.  It is hard to just present a picture of what a child with Down syndrome looks like at a particular age.  A lot  depends upon the child’s medical and health issues.  For instance, has the child had a problem with hearing, especially middle ear pathology?  If so, this can slow down or affect the development of speech production and expressive language.  Does the child demonstrate related difficulties such as autism? This clearly can affect the social interaction and rate of language acquisition.  Does the child have a severe oral-motor problem?  Again, this problem can delay speech production, can affect the quality of spoken speech, and can alter expressive language skills.
It is important, therefore, for parents to understand these issues when seeking information about what to do for their child and what services are available.  How a speech-language pathologist helps a child is clearly related to these and other social, cognitive, emotional, and health issues.
There are several publications available to help parents better understand these issues.  It is not the intent to delve deeply into these areas, but instead to present the communicative skills for young children with Down syndrome.
In order to use the scale, it is important that professionals and parents watch the child play and interact with others.  Observation is the critical means of analysis for the Scale.  Some areas can be measured by directly asking the child to demonstrate a particular skill, while others depend upon making decisions as to whether the child has or does not have a skill.  Children are inconsistent and demonstrate they can do something one time and then can not do it later.  A judgment is necessary to determine whether the skill is consistent, emerging, or not yet obtained.  The scale can be used to measure progress over time, by scoring the instrument on a regular interval, such as every six months.
The Scale has gone through several developments.  The current version has been used on more than 60 infants and toddlers with Down syndrome and has been found to be quite reliable when compared to standardized measure of language and vocabulary.

Developmental Scale for Children with Down Syndrome

The Developmental Scale for Children with Down Syndrome begins at Birth and increases in 4 month steps until age 24 months. At this point it progresses in 12-month steps.  The Scale ends when the child is just turning 6 years of age (or 71 months).  The reason for the difference in the early ages compared to the later ages is that younger children, even children with Down syndrome, progress more rapidly in the younger ages than they do in the older ages.  This is especially true for motor skills and language skills.

Birth to 5 months

During the first stage, Birth to 5 months, a parent can expect their child to react to a sound sometimes and not at other times.  The reason for this is that the child may be congested with a middle ear fluid, or just may not be attending as readily to his environment. Inconsistent responses to sounds are a common occurrence at this age.
Because of this, the child with Down syndrome may or may not turn his/her head toward the sound source and may or may not be watching the parents’ face when they talk.  It is strongly suggested that a child should be seen for an audiologic evaluation since it is well known that middle ear problems are common and children with Down syndrome are even more prone to have a sensori-neural hearing loss.  It is, therefore, important to have the child’s hearing checked early.
Children with Down syndrome seldom vocalize during the first 5 months of life, which often concerns parents.  This concerns us too, but as long as the child’s hearing has been checked and the child does not demonstrate oral-motor problems, it should not be too alarming.  Just keep talking to your child and read books together on a daily basis.  Reading is an excellent teaching tool for speech, language, and cognitive development.  We find many young children, even at 4 – 5 months of age, love to be read too.

6 – 10 months

The children during the second stage, or 6-10 months, begin to watch their parents’ face when being talked too and localize where a sound has come from, especially when the sound is sudden or unexpected.  These children notice their parents’ reprimands, such as, saying “no-no”; but, understanding of words is not really expected yet.
Most children with Down syndrome do not begin to babble or “talk to themselves” until around 10 months of age.  Babbling is an important indicator as to how well the child is doing and whether he or she will be a talker later on; it helps to determine whether a child will or will not have trouble with spoken speech.  Just because a child does not babble does not necessarily mean he or she will not talk later on.  It may, however, indicate that more oral-stimulation and speech-stimulation is needed to assist the child in developing the needed movements for later speech productions.

11 – 15 months

The children at this age are beginning to show signs of language understanding.  Parental reports of vocabulary development indicate that  11- 15 month old children with Down syndrome demonstrate an understanding of about 20 words and try to communicate by looking at the parent, gesturing, or moving as if to say something.  These children want to communicate but the motor speech area in the brain is not developed sufficiently to allow for it.  Thus, we encourage the use of manual signs to allow the children to express their wants and needs.  Oral-motor skills have improved so that now they can chew semi-solid foods, blow bubbles, and can stand up if allowed to hold onto something.  When this occurs, it is a strong indicator that spoken words are about to appear.

16 – 20 months

Comprehension of words, during this stage, has grown to 40-60 words.  The child now should be chewing solid foods, sucking through a straw, standing, and walking.  Children now like to listen to simple stories and are beginning to point to objects and pictures in the story.  These children are more interested in producing sounds and attempt to repeat sounds, especially sounds of animals. However, there are still no intelligible spoken words yet.  Feelings are beginning to be displayed more openly, such as showing displeasure when a toy is removed or throwing a toy on the floor when it will not work.  The child, at this stage, has a clear choice of favorite toys and seeks or requests them, often with gestures.

21 – 25 months

This stage is marked by the obvious comprehension of language.  The child has a wide understanding of words, including nouns, verbs, adjectives, and some prepositions.  He or she is a social person: one who wants to interact with others and be a part of family “events.” The child wants to show others a favorite toy or retrieve an object on request:  the child watches others carefully, by holding good eye contact, waiting, and responding when talked too, or repeating an activity when asked to do something again.  Unfortunately, many children (i.e., approximately 40%) demonstrate signs of poor oral motor skills.  These poor oral motor skills are quite obvious at this stage and can have an effect on the child’s eating, chewing and swallowing.  They also can have an effect on spoken words.
Typically, most children with Down syndrome, at this stage, still do not produce spoken words.

26 – 30 months

The child of 26-30 months is now ready to begin to speak.  This is when the child says his/her own name, labels animals, requests “bottle” or “juice”, and calls for “mommy” and “daddy.”  During this stage, the child should have approximately 10-20 intelligible words.  Comprehension also has grown to where the child understands as many as 150-175 different words.  The child points to his/her toes, eyes, and nose, and follows a simple one step command, such as, “put the block on the chair,” or “put the book away, please.”  The child is also interested in listening to simple stories, either those being read or those being told by someone else, especially about the child’s adventures for that day.
The child with an oral motor problem, however, is less productive in spoken words.  He or she may attempt to speak several words, but few individuals, or only a family member, can understand them.  There may be one or two words that others understand clearly.

31 – 35 months

Children at this stage are more talkative and typically produce 30–80 intelligible words, combined with other non-intelligible words.  Parents often report that the child, at this stage, is trying to say phrases and sentences, but no one really understand them.  Comprehension has now grown to where the child understands as many as 250 words.  These children listen to much longer stories and attend to stories that are 15 – 20 minutes long.  Some spoken two-word combinations are heard, and the child may ask a question by raising his/her pitch at the end of the phrase.  The word “why” is often heard.
Speech sounds, produced during this stage, are typically those that develop early: p, m, n, w, h.; however, they are often omitted at the ends of words.  Weak auditory memory and poor sound-to-symbol associations can account for the poor speech production during this stage.
Children with oral motor impairments tend to produce words with just vowels and produce more sounds that are formed toward the back of oral cavity, such as, k and g.  They have less ability to use their tongue tip or close their lips when producing sounds.   It is for this reason that intelligibility is so poor for this group of children.

36 – 40 months

During this stage, the children become conversationalists:  they engage in short dialogues with others and often use 2 word sentences.  They actually produce up to 150  intelligible words, although there still may be many sound errors.  Typically, these sound errors include substitutions (i.e., t for s, t for th, p for f) or distortions, especially fricatives (i.e., f, v, s, z, sh, ch, zh).  These fricative distortions are not produced with a high clear frequency sound, but instead are produced more like a “slushy” sound.
Children now begin to ask simple questions, recognize nearly all of the primary colors, use both verbs and adjectives in their sentences, and use some morphemes like plurals (dog, dogs), irregular past tense (went), and actions (-ing, running).  Pronoun use includes I and me in the subject position; as well as, you, mine, and your.  Sometimes the child uses the pronouns he and she appropriately, while other times they are confused with the gender.
Children with oral motor impairments omit many sounds.  The omitted sounds occur in the initial position (“-ar” for “car”), in the medial position (“bo-el” for “bottle”) as well as the final position (“bi-” for “big”).  However, their comprehension is similar to other children with Down syndrome, i.e., approximately 250 –words: it is the production of speech that clearly differentiates the two groups.

41 – 59 months

At this stage of development, children with Down syndrome now have a comprehension vocabulary that can reach 900 words.  They are easily producing oral words, 2-3 word sentences, and retelling short stories.  They are beginning to recognize environmental symbols like stop signs, McDonald’s arches, and the sign open.  They may know most letters of the alphabet and have a sight word reading vocabulary of 15-20 words.

60 – 71 months

The highest stage of development for the scale is when the child reaches about 5 years old.  Here the child is producing longer sentences that are usually 3-4 words long but there can be some 5-6 word phrases.  Their comprehension vocabulary can exceed 10,000 words.  They may be producing 400 or more intelligible words, but few signs.  At this age, children with Down syndrome typically decrease their use of manual signs.  They can count 10 objects, know their primary colors, use both verbs and adjectives in their sentences, refer to themselves with a pronoun form, and use regular plural verb forms.  They are now reading short dialogues in stories and will have some word attack skills.

Comparison with Typical Children

It is obvious that children with Down syndrome do not keep up with the rate of communication skills of typically developing children, although there are some noticeable similarities between the groups.  For one thing, at the younger stages (i.e., Birth to months, 6 – 10 months, 11 – 15 months, and 16-20 months), the children with Down syndrome seem to be only around 6 months behind their typically developing peers. An exception to this is the number of spoken words, where the children with Down syndrome tend to lag as much as a year behind.  Also a gap exists in the rate of vocabulary comprehension, where the children with Down syndrome appear to increase their vocabulary comprehension from stage to stage, but not as fast as their typically developing peers.  There are, however, quite a few similarities in gestures, socialization, and playing with toys. These areas seem to lag only slightly behind.
At the later stages, beginning at around 26 months of age, the gap between the children with Down syndrome and their typically developing peers widens. For instance, comprehension and spoken words increase, but even at the 60 – 71 month stage, these skills are comparable only to the typically developing children at 31-35 months of age. Older children with Down syndrome do have concepts and social exchanges that are more like the typically developing children at 36-40 months of age.  Thus, some developmental skills appear to be above the level of their measurable vocabulary and spoken language skills


It is hoped that the Developmental Scale has provided clarification for where children with Down syndrome fit compared to typically developing peers.  It is hoped that it sheds some light on how your individual child is doing.  The value of early intervention, oral motor training, speech stimulation, joint-book reading, and language training has not been discussed.  It is important to realize that many children with Down syndrome are fully included in regular education classrooms.  These children started off much different from their typically developing peers, but through strong parent advocacy and professional assistance, they made outstanding gains.  Your child can do this too.
It is my expectation that in the next few years the Developmental Scale will be outdated: the stages will need to be altered because early and appropriate interventions have made a difference among young children with Down syndrome.  Until then, please use the Scale to determine your child’s progress and use it to help plan for the next stage.


The Developmental Scale for Children with Down Syndrome is scored either with a parent’s input or by directly observing the child’s behavior.  Often times, the actual number of spoken words and oral words are scored by including test results from other tools, like the MacArthur’s Scale for Infants and Toddlers.  The author has normative data on children with Down syndrome acquiring their first oral and sign words and number of words comprehended on the MacArthur.  To score the Developmental Scale for Children with Down Syndrome the examiner should merely place a + sign for all behaviors observed or are reported that are frequently present.  A score of 0 should be marked for all behaviors that are not present.  Mark of ± is provided for all behaviors that occur but not frequently, or in transition.
Only the + scores are calculated per stage.  If a child has all but one + score at a particular age, the child is considered to be at that age.  If the child passes with a + mark for half of the items at any stage, the examiner should take the youngest age and add two months to determine the child’s developmental age.  For example, if the child has the following scores at the 16-20 month level, he or she would be considered to be at 18 months of age.
+ Identifies by pointing
+ Sucks through a straw
+ Chews solid foods
0 Walks (at around 18 months)
+ Seeks toy for appropriate play
0 Listens to simple stories being read (single lines per page)
+ Indicates displeasure when toy is removed
0 Comprehends 40-60 words
0 Recognizes family names
+ Gestures and vocalizes needs
+ Points to objects and pictures
0 Tries to repeat sounds
0 1-2 oral words
This child has passed 7 items and missed 6 items.  Thus, he is about half way through the developmental age of 16-20 months, or 18 months of age.
After scoring your child, move the information to the front cover and make sure you date it.  Remember it is important to realize that children are variable and your judgment or scoring could change within a few weeks.  You may want to rescore the instrument in two months to see if your child still has missing items.


Download the accompanying form here (in PDF format)
Developmental Scale for Children With Down Syndrome – Form Only

Or download the form, along with the above instructions here (in PDF format)
Developmental Scale for Children with Down Syndrome – Instructions and Form