Of all the topics that make FNP candidates panic, pediatric developmental milestones might be the worst. The exam will ask you whether a 9-month-old should be doing X, and you'll have a vague sense it's about right but no confidence. You'll guess. And the AANP and ANCC both love to ask these questions.
Here's the truth: you don't have to memorize 200 milestones. You have to know the inflection points. Once you know those, you can extrapolate.
Pediatric development is patterned. Learn the pattern and the dates fall into place.
The Inflection Points
Memorize these absolutely. They are the most-tested milestones on FNP exams.
2 months
Social smile. Tracks objects past midline. Cooes. Lifts head when prone.
4 months
Laughs. Rolls from prone to supine. Grasps a rattle. Holds head steady.
6 months
Rolls both ways. Sits with support. Babbles. Stranger anxiety begins.
9 months
Sits alone. Crawls. Pincer grasp emerges. Says "mama" and "dada" non-specifically. Object permanence.
12 months
Stands alone, may walk. One to three meaningful words. Waves bye-bye. Drinks from a cup.
15 months
Walks independently. Uses 5 to 10 words. Scribbles. Points to indicate wants.
18 months
Runs awkwardly. Vocabulary 15 to 20 words. Feeds self with spoon. Identifies body parts.
2 years
Two-word phrases. Runs well. Climbs stairs holding railing. Half of speech understandable to strangers.
3 years
Three-word sentences. Pedals tricycle. Copies a circle. Knows full name and age.
4 years
Hops on one foot. Copies a cross or square. Tells stories. Plays cooperatively.
5 years
Skips. Copies a triangle. Counts to ten. Dresses with minimal help.
Red Flags That Win Exam Points
The FNP boards rarely asks you to confirm normal development. It asks you to recognize when development is delayed and what to do about it. Burn these red flags into memory:
- No social smile by 3 months
- Not rolling by 6 months
- Not sitting alone by 9 months
- Not walking by 18 months
- No words by 16 months
- No two-word phrases by 24 months
- Loss of previously acquired skills at any age
The right answer to "what's the next step" when you see one of these is almost always referral for developmental evaluation — early intervention services, audiology, or developmental pediatrics.
Clinical Pearl: Loss of previously acquired skills is an emergency-level concern. It can signal autism regression, neurodegenerative disease, or abuse. Never minimize regression.
The Denver II and ASQ
Know these by name. The Denver Developmental Screening Test II and the Ages and Stages Questionnaire (ASQ) are the two screening tools you'll see referenced. The ASQ-3 is currently the most commonly used in primary care because parents complete it.
Growth Parameters
Quick rules for the boards:
- Birth weight doubles by 6 months, triples by 12 months.
- Head circumference grows 2 cm/month for first 3 months, then slower.
- Anterior fontanelle closes by 18 months. Posterior fontanelle by 2 months.
- First teeth erupt around 6 months. Twenty primary teeth by age 3.
How to Drill This
Make a simple table. Down the left, ages from 2 months to 5 years. Across the top: gross motor, fine motor, language, social/cognitive. Fill it in from memory. Three days in a row.
The trap on the exam is not the milestones themselves — it's the speed at which you need to recognize them. Drill until they're instant.