What is development?
All children grow and develop as they age. Growth refers to the increase in the size of a child in terms of weight and height. On the other hand, as a child becomes older and their brain becomes more mature, children learn increasingly complex skills…which is what we call development.
As learning any skill is based on experiences, in addition to a child’s genetic structure, health status and nutrition, environmental stimulation is essential for appropriate development.
What are developmental milestones?
Developmental milestones are important specific skills that are expected to be reached within a certain age range. The sequence in which milestones are reached is the same in all children- which means that all children will first learn to hold their head, then to sit and then to stand. However not all children reach their milestones at exactly the same age- some are early and some learn late.
What are developmental domains?
Development milestones are grouped into different categories known as domains:
Gross Motor: Skills related to the movement of large muscles and posture
Fine Motor: Skills related to finer movements of the hands and smaller muscles such as precision work and eye-hand coordination
Language: Skills related to verbal and nonverbal communication with others
Cognitive: Intellectual skills relate to learning and understanding (concepts of numbers, colors, letters, reasoning and problem-solving)
Social-Emotional and Behavioral: Interaction with others, interpersonal relationships, feeling and understanding, empathy, and control of emotions.
Key milestones for the first 2 years:
| Age | Gross Motor | Fine Motor | Social-emotional | Language |
| 2 months | Lifts head up when lying on tummy | Follows objects/ people with eyes | Smiles on social contact | Coos (using vowel sounds such as aaah and oooo) |
| 3 months | Holds head steady unsupported | Recognizes mother | ||
| 4 months | Rolls from prone to supine positions | Reaches for objects with both hands and puts them in mouth | Shows emotions like joy, fear | Laughs out loud |
| 5 months | Rolls supine to prone | |||
| 6 months | Sits with support | Reaches for objects with one hand Transfers objects from one hand to another | Recognizes strangers and has stranger anxiety | Says monosyllables (consonants like ba, ma) |
| 8 months | Sits without support, crawls | |||
| 9 months | Stands holding on to furniture Pulls themselves up from a sitting position to standing | Probes objects with index finger Picks up objects using index finger and thumb | Waves bye-bye | Says bisyllables (baba mama) |
| 12 months | Stands without support Walks holding on to furniture (“cruising”) Walks while holding the hand of a caregiver | Throws objects Puts things in and out of a container | Responds to his name and to “No”. | Says 1-2 words with meaning Communicates by pointing to objects |
| 15 months | Walks alone | Scribbles on paper with a crayon | Points to body parts Follows simple 1 step commands | |
| 18 months | Runs | Imitates vertical strokes with a crayon | Copies parents (They pretend to talk on the phone, drive a car) Understands the concept of “mine,” | Uses 10 to 25 words with meaning |
| 24 months | Walks up and down the stairs putting both feet on each step Jumps, kicks a ball, throw overhand | Imitates circles and horizontal lines | Follows two-step instructions | Uses 50 and 200 words, Says short sentences using 2-3 words |
(Note: Different sources provide slightly different age limits for different milestones)
Development in premature babies
Babies born prematurely (before 37 weeks of gestation) have a higher risk of behavioral disorders and learning delay compared to children born at term. When assessing development in preterm babies, the “corrected age” rather than the chronological age is used for the first 24 months after birth.
So what is chronological age? It is the age calculated from the date of birth. Then what is corrected age? That is the age your child would have been had he/she not been born prematurely (ie. From the due date and not the birth date). An example- your baby is now 6 months old from the date of birth but was born 2 months early. Which means that had your baby not been born early, he/ she would have been 4 months old (not 6) therefore he/she would be following milestones of a 4-month old child and not of a 6 months old child.
Red flags
There is an acceptable age range within which children are expected to achieve each milestone. If your child fails to attain a skill beyond that range, it is advisable to consult a pediatrician or an early development specialist for further assessment. The CDC provides simple and easy to understand guidance on what to expect at each age (with pictures) along with the red flags as well as a milestone checklist (go to CDC Developmental Milestones ).