A mother brings her 9-month-old infant for developmental assessment. The infant can sit without support, transfers objects hand-to-hand, has a good pincer grasp, babbles 'mama/dada' non-specifically, and waves bye-bye. The health worker notes the infant does not have a social smile or respond to their own name. Which aspect of development is MOST concerning and what is the MOST likely explanation?

• A Absence of pincer grasp is the most concerning; suggests focal cortical injury
• B Gross motor development (sitting at 9 months) is delayed and is the primary concern
• C Absence of social smile and failure to respond to name are concerning for autism spectrum disorder; social smile should be present by 2 months ✓
• D Non-specific 'mama/dada' babbling is delayed; specific 'dada' should be present by 6 months

Explanation

Social smile is normally present by 6–8 weeks (2 months); its absence at 9 months is a significant red flag indicating either visual impairment, hearing impairment, or autism spectrum disorder. Failure to respond to own name by 9–12 months is a recognized early indicator of ASD. All other milestones described (sitting, transfer, pincer, non-specific babbling, bye-bye) are appropriate for 9 months. Non-specific 'mama/dada' is expected by 9–10 months; specific use occurs by 12–14 months. Social-communicative red flags require immediate investigation. Referral for audiological assessment and formal developmental evaluation is warranted.

Reference: Ghai Essential Pediatrics, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.