Understanding Developmental Milestones: A Pediatric Neurology NP's Guide

Introduction

You check your baby app and see that your 7-month-old "should" be sitting independently. But your baby still topples over after a few seconds. Your neighbor's baby is already crawling. A quick Google search sends you down a rabbit hole of developmental delays, early intervention, and worst-case scenarios. By midnight, you're convinced something is wrong.

Sound familiar?

As a Pediatric Nurse Practitioner specializing in neurology with over 8 years of experience evaluating children with developmental concerns, I see worried parents every single day. The most common reason I evaluate infants is for concerns about delayed sitting, crawling, walking, or talking. And here's what I want you to know: milestone anxiety is nearly universal, but most of the time, your child is developing just fine.

That said, developmental milestones matter. They're our best tool for identifying children who need support early, when intervention makes the biggest difference. The key is understanding what milestones actually mean, how much variation is normal, and when concern is warranted.

This guide is a clinical interpretation tool—helping you understand what I look for when evaluating development, what raises red flags versus what's normal variation, and the science behind why timing within normal range doesn't predict outcomes. You'll learn:

• What developmental milestones really are and why we track them
• Why you should think pass/fail, not grading scale (and the neuroscience behind this)
• How your baby's brain development drives milestone achievement
• The difference between normal variation and true developmental delay
• Clear red flags that warrant professional evaluation
• The science behind what actually supports development

Looking for a practical tracking system instead? Jump to the step-by-step tracking guide.

Let's take the guesswork out of developmental understanding. By the end of this article, you'll know what's normal, what's not, and why timing within the normal range is clinically meaningless.

What Are Developmental Milestones (And Why They Matter)

Developmental milestones are specific skills or behaviors that most children can do by a certain age. They're based on decades of research observing thousands of children and identifying typical patterns of development.

How milestones are established: Researchers study large, normative samples of children—thousands of babies and toddlers—and document when specific skills emerge. They use percentiles to determine age ranges: if 90% of children are walking by 18 months, that becomes the upper limit of the "typical" range. This is why milestone ranges are wide—they capture normal human variation.

We track milestones across five main categories:

• Gross motor: Large muscle movements like rolling, sitting, crawling, walking
• Fine motor: Small muscle control for reaching, grasping, self-feeding
• Speech and language: Understanding and using communication
• Social-emotional: Bonding, emotional regulation, interacting with others
• Cognitive: Thinking, learning, problem-solving

Why we track them: The point of developmental screening is to identify kids who might benefit from early support. Research consistently shows that early intervention—starting therapy or support services before age 3—leads to significantly better outcomes for children with developmental delays.

The American Academy of Pediatrics (AAP) recommends formal developmental screening at 9, 18, and 30 months, with autism-specific screening at 18 and 24 months. Expert screening is crucial, but parents observe their children daily, making you the first and best chance at identifying areas, in which your baby might need specific support.

Here's what milestones are NOT: Milestones are not rigid deadlines. They're not predictors of future success or abilities. And most importantly, they are not a grading system.

The Pass/Fail Framework: Why Timing Within Normal Range Doesn't Matter

This is one of the most important concepts I want every parent to understand, and it's not just about reducing anxiety—it's about the actual science of child development.

Think of milestones as pass/fail, not as a grading system. Within the normal range, timing is clinically and developmentally meaningless. A baby who walks at 10 months doesn't get an A+ while one who walks at 16 months gets a C. They both pass. They're both developing typically. And here's the crucial part: research shows no long-term differences in motor skills, intelligence, or any other developmental outcome based on when within the normal range a child achieves milestones.

Why Timing Doesn't Predict Outcomes (The Science)

When parents see their baby achieve a milestone "early," they often feel proud—like their child is ahead or advanced. When a milestone comes "late" (but still within normal range), they worry their child is behind. This is a natural parental response, but it's not supported by developmental science.

Here's what research shows:

Motor milestone timing within normal range doesn't predict later motor skills. Multiple longitudinal studies have followed children who walked at 10 months versus 16 months. By age 3-4, there are no detectable differences in gross motor abilities, coordination, or athletic potential. The early walker has no advantage. The later walker has no disadvantage.

Early language doesn't predict later language ability within normal limits. A child who says their first word at 10 months and one who says it at 15 months show equivalent language skills by preschool, assuming both are within the typical range. What matters is steady progress and reaching language milestones within the broad normal window—not where within that window they fall.

Milestone timing reflects individual variation in neurodevelopmental expression, not capability. Think of it like this: some babies get their first tooth at 4 months, others at 12 months. This timing difference doesn't predict dental health, adult teeth quality, or anything meaningful—it's just genetic and individual variation. The same is true for developmental milestones within the normal range.

What Actually Drives Timing Variation

When a typically-developing child achieves milestones at different points within the normal range, it reflects:

• Temperament: Cautious babies take longer to walk independently because they're assessing risk. Bold babies may walk earlier but take more tumbles. Neither temperament predicts future motor ability—they're just different approaches to the same developmental task.

• Focus and neurological prioritization: Babies' brains often focus developmental energy on different domains at different times. A baby intensely focused on language acquisition may progress more slowly in motor domains temporarily, then catch up quickly. This shifting focus is normal and doesn't indicate overall capability.

• Body type and physical characteristics: Petite babies often roll and crawl earlier simply because there's less body mass to coordinate. Bigger babies may take longer to walk because there's more to balance. By toddlerhood, these differences disappear.

• Opportunity and environment: Babies with more floor time may crawl earlier. Babies in cultures with more infant carrying may walk later. These environmental factors influence timing without affecting ultimate developmental outcomes.

• Genetic variation: Just like height, hair color, and metabolism, neurodevelopmental timelines have a genetic component that creates natural variation within the typical range.

None of these factors predict intelligence, future ability, or long-term outcomes. They're just different expressions of normal development.

Why We Use Ranges, Not Single Ages

The CDC and AAP provide milestone ranges (like "walking: 9-18 months") specifically because normal variation is wide. These ranges aren't showing you a spectrum from "slow" to "fast"—they're showing you the boundaries of typical neurodevelopment.

The clinically meaningful number is always the upper limit of the range. When you see "walking: 9-18 months," the important number is 18 months. That's when we'd begin to be concerned if a child isn't walking yet. The 9-month mark is simply showing you that some babies walk quite early—not that walking at 9 months is better or more advanced than walking at 16 months.

The Real Purpose of Milestone Tracking

If timing within the normal range doesn't predict anything, why track milestones at all?

We track to identify the small percentage of children who fall outside the typical range—those who would benefit from early intervention. A child not walking by 18 months needs evaluation. A child not talking by 18 months needs evaluation. These are children whose development may be following an atypical path, and early support makes a meaningful difference.

But for the vast majority of children—those achieving milestones anywhere within the normal range—tracking serves a different purpose: reassurance that development is proceeding typically, even if it doesn't match your neighbor's baby or the earliest examples in your milestone app.

Reframing Your Mindset

When you look at milestone charts, train yourself to think:

• ✓ "Is my child within the range?" not "Where in the range are they?"
• ✓ "Are they making steady progress?" not "Are they ahead?"
• ✓ Pass or not yet passing—not grading on a curve

This isn't just about reducing parental stress (though that matters too). It's about understanding developmental science accurately. Within the normal range, variation is just that—variation. It doesn't mean anything about your child's future, their intelligence, or their abilities.

A baby who walks at 10 months and one who walks at 16 months are both typically developing. They're both passing. And by the time they're 4 years old, you won't be able to tell who walked when.

Ready to start tracking your child's development? Use this practical step-by-step system that takes the stress out of milestone monitoring.

How Brain Development Drives Milestones

Understanding a bit of neuroscience helps explain why milestones happen when they do—and why variation is normal.

Think of brain development like building a house: You need the foundation before the frame, the frame before the wiring, and the wiring before the finishing touches. Your baby's brain follows this same sequential pattern.

Your baby is born with about 100 billion neurons, roughly the same number they'll have as an adult. But these neurons aren't well connected yet. During the first years, your child's brain creates up to 1 million new neural connections per second through a process called synaptogenesis.

This development follows predictable patterns:

1. Bottom-up development: The brain develops from simpler to more complex functions. Motor control progresses from head to toe and from center to extremities. That's why babies gain head control before trunk control, and trunk control before leg control.

2. Sequential skill building: Later skills depend on earlier ones. A baby needs trunk stability before they can reach effectively. They need to sit before they can crawl (though some babies skip crawling and do just fine).

3. Critical and sensitive periods: Certain windows are especially important for specific skills. Language development, for example, has a sensitive period in the first few years when the brain is particularly primed for language learning.

4. Pruning and refinement: After the explosion of connections, the brain prunes unused connections and strengthens frequently used ones. This is why practice matters—but also why there's natural individual variation.

The key takeaway: Your baby's brain follows a biological blueprint, but exact timing varies naturally—just like some children get their first tooth at 4 months while others wait until 12 months.

Milestone Categories Explained

Let's break down each developmental domain from a clinical perspective—what each domain tells us about neurodevelopment, why it matters, and what patterns raise concern versus what's simply normal variation.

For a detailed, practical guide on what specific behaviors to observe and track in each domain, see the step-by-step tracking guide.

Gross Motor Development

What it is: Large muscle movements and coordination involving the trunk, arms, and legs.

Why it matters: Gross motor skills are often the most visible milestones and are crucial for a child's independence and exploration. They also reflect neurological maturation and muscle tone.

Typical progression (first year):

• 2-3 months: Lifts head during tummy time, begins pushing up on arms
• 4-6 months: Rolls both directions, sits with support
• 6-8 months: Sits independently, may begin army crawling
• 8-10 months: Crawls, pulls to stand
• 10-14 months: Stands independently, walks with support
• 12-18 months: Walks independently

Fine Motor Development

What it is: Small muscle control, particularly in the hands and fingers, plus hand-eye coordination.

Typical progression:

• 2-4 months: Brings hands to mouth, swipes at objects
• 4-6 months: Reaches for and grasps objects, transfers toys hand to hand
• 6-9 months: Raking grasp, begins pincer grasp (thumb and finger)
• 9-12 months: Refined pincer grasp, points with index finger
• 12-18 months: Stacks blocks, scribbles, self-feeds finger foods

Red flags:

• Persistent fisting after 4 months
• Not reaching for objects by 6 months
• No pincer grasp by 12 months
• Significant hand preference before 18 months (can indicate weakness on one side)

Speech and Language Development

What it is: Both receptive language (understanding) and expressive language (speaking), plus pre-language skills like babbling and gesturing.

Typical progression:

• 2-4 months: Coos, responds to voices
• 4-6 months: Babbles, experiments with sounds
• 6-9 months: Babbles in varied tones, responds to name
• 9-12 months: Says first words, understands simple commands
• 12-18 months: Vocabulary expands to 10-20 words, follows simple directions
• 18-24 months: 50+ words, beginning to combine words

Red flags:

• Not responding to sounds by 6 months
• No babbling by 9 months
• No words by 16 months
• No two-word combinations by 24 months
• Loss of previously acquired language skills (regression)

Social-Emotional Development

What it is: Bonding, emotional expression, reading social cues, and interacting with others.

Typical progression:

• 2-3 months: Social smiles, tracks faces
• 4-6 months: Laughs, shows excitement when seeing familiar people
• 6-9 months: Shows clear preferences for familiar people, may show stranger anxiety
• 9-12 months: Plays social games (peek-a-boo), shows affection
• 12-18 months: Shows separation anxiety, imitates behaviors
• 18-24 months: Parallel play, shows empathy, points to show interest

Red flags:

• No social smile by 3 months
• Doesn't make eye contact by 6 months
• No shared enjoyment or social reciprocity by 9 months
• Doesn't respond to name by 12 months
• No interest in other children by 18 months

Cognitive Development

What it is: Thinking, learning, problem-solving, and memory.

Typical progression:

• 2-4 months: Recognizes familiar faces, shows curiosity
• 4-6 months: Explores cause and effect, looks for partially hidden objects
• 6-9 months: Object permanence emerges, explores object properties
• 9-12 months: Uses objects correctly (cup for drinking), solves simple problems
• 12-18 months: Imitates actions, simple pretend play
• 18-24 months: Sorts shapes and colors, more complex pretend play

Red flags:

• Lack of curiosity or exploration by 6 months
• No object permanence by 12 months
• No functional play with toys by 18 months
• No pretend play by 24 months

Normal Variation vs. Developmental Delay: Clinical Patterns to Recognize

This is where clinical experience matters most. As a pediatric neurology NP, I evaluate children daily to determine whether their development reflects normal variation or concerning delay. Here's how I think about this distinction:

The Range of Normal is Wide (And Clinically Meaningful)

Remember the pass/fail framework we discussed earlier. Within the normal range—whether your child is at the early end, middle, or late end—they're passing. The variation is developmentally and clinically insignificant.

How I read milestone ranges clinically: When evaluating a child, I focus on the upper limit of the normal range. That's the clinically meaningful cutoff. Everything before that upper limit is variation, not delay.

For example, with walking (9-18 months): If I see a 14-month-old who isn't walking yet, I'm not concerned—they're well within the normal range. At 17 months, I start paying closer attention and might provide anticipatory guidance. At 18+ months without walking, I recommend evaluation.

Multiple milestone domain delays The more domains in which a child is approaching the delay threshold, or has surpassed a delay threshold, then the more concerned I would be.

Statistical reality of percentiles: Your child will naturally fall at different percentiles for different skills. This is expected and normal. A baby at the 75th percentile for language and 25th percentile for gross motor is developing typically in both domains—they're just expressing the normal range differently in each area.

What Creates Timing Variation (The Clinical View)

From a neurodevelopmental perspective, timing variation within the normal range occurs due to:

Prematurity and gestational age at birth: This is the one factor we must adjust for clinically. Premature infants need age correction (subtracting weeks premature from chronological age) because their neurological maturation follows their biological timeline, not their birth date. I correct age until 24-30 months for most premature infants, longer for those born before 32 weeks.

Neurodevelopmental prioritization: Brain development doesn't proceed uniformly across all domains simultaneously. Infants often show bursts of progress in one domain while another temporarily plateaus. This shifting focus is a normal pattern of neurodevelopment, not a concerning delay.

Temperamental factors: Behavioral inhibition (cautiousness) versus behavioral approach (boldness) influences when children attempt new motor skills. Both temperaments are normal neurobiological variations; neither predicts motor ability or developmental outcomes.

Environmental input and opportunity: Consistent floor time, responsive interaction, and opportunities for movement practice influence timing. However, these factors work within the child's neurological readiness—you cannot advance development beyond what the brain is ready for, but you can provide the conditions that allow readiness to be expressed.

Genetic and constitutional factors: Body proportions, muscle fiber composition, and individual neurological variation all contribute to timing differences that have no bearing on developmental outcomes.

When Variation Becomes Concerning

I look for these patterns when evaluating whether a delay needs intervention:

1. Missing multiple milestones across domains One delayed skill might be variation. Multiple delayed skills across different areas raises concern.

2. Significant delay (beyond the wide range) Not walking by 18 months warrants evaluation. Not saying single words by 18 months warrants evaluation.

3. Regression (loss of skills) This is always concerning and requires immediate evaluation. If your child had skills and lost them, call your pediatrician today.

4. Persistent asymmetry Consistently using only one side of the body or significant differences between left and right can indicate neurological concerns.

5. Atypical quality of movement Not just whether milestones are met, but how. Abnormal muscle tone (too stiff or too floppy), repetitive movements without purpose, or unusual postures can indicate underlying concerns.

6. Multiple soft signs Individually minor concerns that cluster together—poor eye contact plus no babbling plus motor delays, for example.

When to Seek Evaluation

Don't wait for your child's scheduled well-visits if you have concerns. Trust your instinct as a parent—you know your child best.

Important reassurance: Seeking evaluation never hurts, and often provides peace of mind. Many children referred for evaluation are found to be developing typically. Even if delays are identified, early intervention leads to better outcomes. There's no downside to getting your concerns checked out.

Formal Developmental Screening Schedule

The AAP recommends screening at:

• 9 months: General developmental screening
• 18 months: General developmental + autism screening
• 24-30 months: General developmental + autism screening

Your pediatrician uses standardized screening tools (like the Ages & Stages Questionnaire or Survey of Wellbeing of Young Children) to assess development objectively.

Red Flags by Age

By 3 months:

• Doesn't seem to notice their hands
• Doesn't smile at people
• Can't support head
• Doesn't respond to loud sounds

By 6 months:

• Doesn't roll in either direction
• Doesn't reach for objects
• Seems very stiff or very floppy
• No babbling sounds
• Doesn't show affection for caregivers

By 9 months:

• Can't sit without support
• No back-and-forth babbling
• Doesn't respond to their name
• Doesn't recognize familiar people

By 12 months:

• Isn't crawling or showing alternative mobility
• Can't stand with support
• No single words ("mama," "dada")
• No gestures (waving, pointing, shaking head)
• Doesn't play gesture games like peek-a-boo

By 18 months:

• Isn't walking
• Says fewer than 6 words
• Doesn't point to show things to others
• Loss of any previously acquired skills

By 24 months:

• Doesn't use 2-word phrases
• Doesn't imitate actions or words
• Doesn't follow simple instructions
• Doesn't know function of common objects

The Regression Red Flag

I cannot emphasize this enough: Loss of previously acquired skills always warrants immediate evaluation. Don't wait. Don't "watch and see." If your child:

• Stopped saying words they used to say
• Lost motor skills (could crawl, now doesn't)
• Stopped making eye contact
• Lost interest in people or activities they enjoyed

Call your pediatrician immediately. While there are benign causes (temporary regression during illness or major life changes), regression can also indicate serious conditions requiring prompt intervention.

What Parents Can Do to Support Development: The Science Behind the Strategies

The good news: The most effective developmental support comes from simple, everyday interactions—not expensive programs or products. Here's the science behind what actually matters.

Why Responsive Interaction Drives Development

The neuroscience: Infant brain development is fundamentally social. When you respond to your baby's coos, babbles, and gestures, you're not just being nice—you're literally building neural pathways for communication, emotional regulation, and social cognition.

This "serve and return" interaction (Harvard Center on the Developing Child's term) creates the strongest foundation for language, social-emotional development, and even cognitive skills. The back-and-forth pattern—baby vocalizes, you respond, baby responds to you—is more neurologically powerful than any educational toy or program.

What the research shows: Studies tracking children from infancy through school age consistently find that the amount and quality of language exposure (specifically, responsive back-and-forth conversation) predicts language skills, reading ability, and even academic success better than socioeconomic factors alone.

The Critical Role of Movement and Floor Time

Why it matters neurologically: Motor development isn't just about muscles—it's about brain development. When babies move, they're building not just strength but also spatial awareness, problem-solving skills, and even cognitive abilities.

Research on infant motor development shows that babies who have more opportunity for unrestricted movement (floor time rather than container time) develop motor skills within the expected timeline and show better spatial cognition. Containers (swings, bouncers, jumpers, seats) restrict the movement patterns necessary for motor skill development.

The clinical perspective: In my neurology practice, one pattern I consistently see in children with motor delays is excessive container time in infancy. While containers don't cause neurodevelopmental disorders, they do limit opportunities for typical motor development to be expressed. Conversely, generous floor time allows babies to practice the movement patterns their developing brains are primed to learn.

For specific guidance on implementing floor time and other developmental support strategies, see the practical tracking guide.

What Research Shows Doesn't Predict Outcomes

Understanding what doesn't matter is just as important as knowing what does:

Expensive "educational" products: No research supports the use of special toys, videos, or programs for enhancing infant development. Your baby's brain develops through real-world interaction, not screen-based or product-driven "enrichment." Simple toys (blocks, balls, stacking cups) support development just as well as expensive marketed alternatives.

Early milestone achievement: As we discussed in the pass/fail framework, achieving milestones early (within the normal range) doesn't predict better long-term outcomes. The baby who walks at 10 months shows no motor advantage by preschool compared to the baby who walks at 16 months.

Intensive parent-directed teaching: Drilling flashcards, teaching baby sign language for developmental advantage (as opposed to for communication), or other directive teaching approaches have not been shown to accelerate development or improve outcomes. Follow-the-child interaction is more effective than parent-directed teaching for infant development.

The Comparison Trap: Why It's Neurologically Meaningless

Every parent compares their child to others—it's human nature. But from a neurodevelopmental perspective, these comparisons are clinically meaningless.

Your neighbor's baby walking at 10 months and your baby walking at 15 months are both expressing normal neurodevelopmental variation. By age 4, you won't be able to identify which child walked when by observing their motor skills. The early walker has no detectable advantage; the later walker has no disadvantage.

What to focus on instead: Steady progress within your child's individual timeline, engagement and curiosity, and achievement of milestones within the broad normal range.

When Documentation Becomes Clinically Useful

If you have concerns about your child's development, documenting patterns with video can be invaluable for healthcare providers. Video captures what's difficult to describe in words and allows clinicians to observe patterns we might not see in a brief office visit.

For detailed guidance on what to track and how to share observations with your pediatrician, see the step-by-step tracking system.

Key Takeaways

• ✓ Think pass/fail, not grading scale. Within the normal range, timing is developmentally meaningless. A baby who achieves a milestone early versus late (both within normal range) shows no differences in long-term outcomes.

• ✓ The only clinically meaningful number is the upper limit. Everything before that is normal variation. Focus on whether your child is within the range, not where in the range they fall.

• ✓ Your child's individual timeline reflects normal neurodevelopmental variation. Early in some areas, later in others—this is typical development, not a pattern of concern.

• ✓ Regression (loss of skills) always requires immediate evaluation. This is the most important red flag. Also concerning: no response to sounds, no social connection, delays beyond the normal range.

• ✓ Trust your parental instinct about concerning patterns. If something feels off, seek evaluation. Early intervention makes a difference, and many evaluations provide reassurance.

• ✓ Brain development is driven by responsive interaction and movement opportunity. Expensive products, early achievement, and parent-directed teaching don't improve developmental outcomes.

• ✓ Ready to track your child's milestones? Use this practical step-by-step system designed to reduce stress while ensuring you don't miss important developmental patterns.

Frequently Asked Questions

Q: My baby skipped crawling and went straight to walking. Is this a problem?

A: Not at all. About 10-15% of babies skip crawling entirely, using scooting, rolling, or other methods to get around before walking. What matters is that they're finding ways to be mobile and explore. As long as they're walking independently by 18 months and showing typical development in other areas, skipping crawling isn't concerning.

Q: Should I correct my baby's age if they were born prematurely?

A: Yes, for milestone tracking. If your baby was born 2 months early, subtract 2 months from their chronological age when comparing to milestone charts, typically until age 2-3. A 12-month-old baby who was born 8 weeks early would be expected to meet milestones for a 10-month-old. Always mention prematurity to your pediatrician.

Q: My child is developing normally but isn't talking much. When should I worry about speech?

A: This depends on age. By 12 months, most babies have 1-2 words. By 18 months, I want to see at least 6-10 words and understanding of simple commands. By 24 months, children should have 50+ words and be combining two words together ("more milk," "daddy go"). If your 18-month-old understands everything but isn't talking much, that's less concerning than a child who both isn't talking and isn't understanding. But no words by 18 months warrants a speech evaluation.

Q: How much variation is normal between siblings? My first child was much faster at everything.

A: Enormous variation between siblings is completely normal. Even identical twins can have different developmental timelines. Birth order, temperament, and individual differences all play a role. Unless your second child is missing milestones outside the normal range, different isn't concerning—it's just different.

Q: My baby seems behind in motor skills but ahead in language. Is this a problem?

A: Not typically. It's very common for children to focus their developmental energy in different domains at different times. A baby concentrating on language might progress more slowly with motor skills, and vice versa. What would be concerning is significant delays across multiple domains, not uneven development.

Q: Is there anything I can do to help my baby reach milestones faster?

A: You can support development through responsive interaction, plenty of floor time, and following your child's interests—but you can't (and shouldn't try to) accelerate their neurodevelopmental timeline. Pushing children to achieve milestones before they're developmentally ready can actually be counterproductive and stressful for everyone. Focus on providing opportunities and letting your child develop at their own pace.

Q: When is early intervention recommended, and what does it involve?

A: Early intervention services are recommended when a child has a developmental delay or diagnosed condition that affects development. Services might include physical therapy, occupational therapy, speech therapy, or developmental therapy, depending on needs. In the United States, children under 3 are eligible for evaluation through state Early Intervention programs (often at no cost to families). The earlier intervention starts, the better the outcomes, which is why screening and early identification matter.

Q: How do I actually track my child's milestones without it becoming overwhelming?

A: Use a simple system that takes just 5-10 minutes per month. The step-by-step tracking guide walks you through choosing a tracking method (app, notebook, or printable chart), what to observe in each developmental domain, and how to share your observations with your pediatrician effectively.

Q: My pediatrician said to "wait and see" but I'm still worried. What should I do?

A: Trust your instinct. You can always seek a second opinion or request a developmental evaluation even if your pediatrician isn't concerned. You can also contact your state's Early Intervention program directly—you don't need a referral. That said, pediatricians see hundreds of children and have a good sense of typical variation. If they're not concerned and your child is making steady progress, they're probably right. But ongoing, persistent worry deserves investigation, if only for your peace of mind.

Q: My child was meeting milestones on time but seems to have slowed down. Is this normal?

A: It can be normal for developmental progress to appear uneven—children often focus their energy on one domain at a time. For example, a baby learning to walk might temporarily plateau in language development. However, true regression (losing skills they previously had) is always concerning and requires immediate evaluation. If your child is still progressing but at a slower pace, mention it at your next pediatrician visit. If they've stopped progressing entirely or lost skills, call your pediatrician now.

Q: Do boys really develop slower than girls?

A: This is a common belief, but the reality is more nuanced. On average, there are small statistical differences: girls may talk slightly earlier, boys may have slightly earlier gross motor skills. But these are population-level averages with enormous individual variation. Plenty of boys are early talkers and plenty of girls are late talkers. We use the same milestone guidelines for both sexes because the differences are so small and the variation within each sex is so large. Being a boy doesn't excuse significant delays or mean you should wait longer to seek evaluation.