TOPIC 11: Development of a 9- to 12-month-old infant
OFFICIAL ABP TOPIC:
Recognize, evaluate, and manage both normal and atypical development of a 9- to 12-month-old infant (social, emotional, language, gross motor, and fine motor)
BACKGROUND
The period between 9 to 12 months is a critical time of rapid development. Infants are becoming more physically mobile, communicating intentionally, engaging in social interactions, and demonstrating early problem-solving skills. Pediatricians play a crucial role in monitoring this development, identifying atypical patterns, and intervening early when delays are suspected.
DEVELOPMENTAL SURVEILLANCE MILESTONES
Developmental surveillance is performed at preventive visits through history and observation. The purpose is to identify children with developmental delay or at risk for developmental delay. Developmental surveillance should include the following:
- Elicit caregiver concerns.
- Record a developmental history and ask about current developmental milestones.
- Observe interactions between child and caregiver.
- Identify risk factors (e.g., prenatal exposures or infections, birth complications, medical or genetic conditions).
- Identify protective factors (e.g., supportive family, caregiver engagement, interaction with other children).
In 2022, the CDC and AAP updated their developmental surveillance milestones to help parents and providers understand whether children are developing typically for their age. These evidence-informed milestones are the age at which ≥75% of children would be expected to demonstrate these skills.
While the milestones below may help parents and clinicians identify children who need further evaluation for a developmental delay, they are NOT a substitute for validated screening tools. Developmental screening refers to standardized testing that identifies children who may be at risk for a developmental disorder. Screening with a tool such as an Ages & Stages Questionnaire should be performed whenever a caregiver or provider has concerns about development or if a child is not meeting the developmental milestones above. In addition, all 9-month-olds should get developmental screening during their 9-month well-child visit.
SURVEILLANCE MILESTONES WHICH ≥75% 9- TO 12-MONTH-OLD INFANTS DEMONSTRATE
| Age |
SOCIAL/EMOTIONAL |
LANGUAGE |
COGNITIVE |
MOTOR |
|
9 MONTHS |
• Acts clingy or shy around strangers • Shows a range of emotions like anger, happiness, sadness • Responds to name by turning or looking • Reacts to separation from caregiver (looks, reaches, cries) |
• Babbles with varied sounds (e.g. “mamama,” “babababa”) • Raises arms to be picked up |
• Looks for objects like a spoon or toy when dropped out of sight • Bangs two objects together |
• Gets to sitting position by herself • Sits without support • Rakes food toward himself with fingers • Transfers objects from hand to hand |
|
12 MONTHS |
• Plays games with others like pat-a-cake |
• Waves bye-bye |
• Puts object in a container, like block in a cup • Looks for objects he sees the caregiver hide (e.g., toy under blanket) |
• Pulls to stand • Walks holding onto furniture • Picks up small objects between thumb and pointer finger • Drinks from a cup without a lid as caregiver holds it |
|
• Calls parent “mama” or “dada” or another nickname • Understands no (pauses or stops when said)
|
EVALUATION OF ATYPICAL DEVELOPMENT
When developmental concerns arise through surveillance milestones review or caregiver report, a systematic evaluation is warranted.
- Administer a validated screening tool such as the Ages & Stages Questionnaire.
- Perform a thorough physical and neurological exam to assess growth, dysmorphic features, reflexes, tone, and development.
- Review newborn metabolic screen and updated social, family, and environmental history.
- Perform hearing and vision screen.
- Order lab tests such as lead levels or genetic testing as indicated.
- Consider developmental-behavioral evaluation by a medical specialist (e.g., developmental-behavioral pediatrician, pediatric neurologist, or child psychiatrist).
- Consider brain imaging if structural anomalies are suspected.
MANAGEMENT OF ATYPICAL DEVELOPMENT
Any infant who screens positive for a possible developmental problem should be referred to early intervention for further evaluation and possible therapeutic services. If a genetic or psychiatric disorder is identified, it should be managed appropriately with close follow-up and collaboration with other specialists as needed. A multidisciplinary approach is often helpful for treating developmental delays:
- Physical therapy to address motor delays and abnormal tone.
- Speech therapy for receptive/expressive language and feeding issues.
- Occupational therapy to aid fine motor, self-care, sensory processing.
- Behavioral interventions for social-communication deficits.
- Social work involvement to connect families with community resources.