Signs of Developmental Delay: When to Talk to Your Pediatrician

Every parent watches their baby's development with a mix of wonder and low-level anxiety. Is this normal? Should they be doing more? Should I mention it at the next visit? The good news is that developmental variation is wide, and many children who seem "a little behind" in one area catch up without any intervention. But some patterns are genuinely worth knowing about — because early identification and early support consistently lead to better outcomes.

Understanding Milestones and Their Variability

Developmental milestones are skills that most children in a given age group can perform. They're expressed as ranges — not precise ages — because healthy development varies meaningfully between individual children.

When pediatricians assess milestones, they're looking across four domains:

A concern in one domain without delays in others is different from concerns across multiple domains. The pattern matters more than any individual milestone. For the range of services available to support these concerns, early intervention for children explains the assessment and referral process.

GrowthKit · Free for iPhone

Track every milestone, instantly.

WHO growth charts·Percentile tracking·Doctor-ready PDF

Download

Age-by-Age Red Flags

These are evidence-based red flags — not "your baby should definitely be doing this by this date," but signs that warrant a conversation with your pediatrician at the earliest opportunity.

Source: AAP Bright Futures, CDC Developmental Milestone checklists (2022 revision)

Red Flags for Autism Spectrum Disorder Specifically

Autism can present in the first year of life. Specific signs that warrant evaluation independent of other milestones:

• No back-and-forth social smiling by 6 months
• Not sharing enjoyment or interest with others (pointing, showing) by 12 months
• No response to name consistently by 12 months
• No joint attention (looking where a caregiver points) by 14 months
• Limited or no pretend play by 18 months
• Any loss of language or social skills at any age

Early identification of autism — ideally before 3 years — significantly improves outcomes because it unlocks access to early intensive behavioural and developmental supports at the most neuroplastic period of development.

The Single Most Important Question: Both Directions

The milestone question works in two directions. Late is worth monitoring — but very early acquisition of skills in isolation can also occasionally signal something worth noting. A baby who appears to repeat sounds or recite sequences unusually early, combined with limited social interaction, is a different pattern from a typically advanced child.

Most of the time, early milestones are simply a sign of a capable, engaged child. But in context with other observations, they're worth mentioning.

What Happens When You Raise a Concern

The most useful thing you can do is raise concerns early rather than taking a "wait and see" approach. Here's what typically follows:

1. Pediatrician assessment: Observation and developmental screening tools at the appointment
2. Referral for specialist evaluation if screening is positive: developmental paediatrician, speech pathologist, physiotherapist, or occupational therapist depending on the domain
3. Early intervention services: In the US, children under 3 qualify under IDEA Part C for free evaluation and services. In the UK, this is managed through local authority teams and NHS paediatric services
4. Formal assessment: Typically takes several weeks; involves standardised developmental testing

Early intervention — therapy starting before age 3 — is consistently shown to produce better outcomes than waiting. The brain is highly plastic in the first 3 years, and targeted support can significantly change a child's developmental trajectory.

How to Bring Concerns to Your Pediatrician

Be specific rather than general. Instead of "I'm worried they're a bit slow," try:

• "They're 12 months old and still not pointing. Is that something we should look at?"
• "They said a few words at 13 months but seem to have stopped. Should we check their hearing?"
• "They don't respond to their name most of the time — I have to be very close or touch them."

Specific observations give your pediatrician something concrete to assess and document. Vague concerns are harder to act on.

Trust your instincts. Parents who know their child well often notice something is different before it’s formally identified. You don’t need certainty to raise a concern — you just need to say what you’re observing. Your pediatrician’s job is to help interpret it. If a language concern is specifically what you’re tracking, when do babies start talking has the precise month-by-month communication milestones.