Developmental Delays in 15-Month-Old Infants

Language Development

Single words should be present by 15 months, and their absence represents a clear developmental delay requiring prompt attention, according to the American Academy of Pediatrics 1
Language regression or failure to develop language can be an early indicator of autism spectrum disorder (ASD), with children who lose language milestones between 12-18 months or fail to develop them requiring comprehensive developmental assessment 2, 3

Independent walking is NOT expected at 15 months, and the American Academy of Pediatrics guidelines indicate that independent walking should be assessed at the 18-month visit, not at 15 months 1

Hearing impairment must be ruled out first in children with language delays, with formal hearing screening recommended, as even mild hearing loss can significantly impact language development 2, 3
Autism spectrum disorder should be considered, particularly if accompanied by social interaction difficulties, restricted interests, or regression of previously acquired skills 2, 3, 4
Global developmental delay may present with language delay as the most obvious early sign 1

Refer immediately to early intervention services (Child Find/Early Intervention programs) without waiting for further diagnostic clarification, as recommended by the American Academy of Pediatrics 1, 5
Perform comprehensive hearing evaluation with formal audiologic testing, not just office screening 2, 3
Assess for autism spectrum disorder features, including social communication difficulties, restricted interests, and repetitive behaviors 2, 3, 4