Growth and Development Milestones

Pediatrics · Growth & Development·Updated 2026-10-28

What it is

Development follows a predictable sequence: cephalocaudal (head control before sitting, sitting before walking) and proximodistal (whole-arm reaching before a pincer grasp). Children vary in rate but not in order, so the nurse compares each child with the expected range and watches for a skill that is late or lost. Loss of a previously acquired skill at any age is never normal and needs prompt referral.

What the NCLEX focuses on

Primitive reflexes fade on schedule: palmar grasp by 3 months, Moro and rooting by 4 months, Babinski after 1 year; persistence signals a neurologic problem.
Birth weight doubles by 5 to 6 months and triples by 12 months; the posterior fontanel closes by 6 to 8 weeks and the anterior by 12 to 18 months.
Use corrected age for preterm infants until 2 years: an 8-month-old born at 28 weeks is assessed against 5-month milestones.
Play: solitary (infant), parallel beside peers (toddler), associative (preschool), cooperative with rules (school-age).
Erikson: trust (infant), autonomy (toddler), initiative (preschool), industry (school-age), identity (adolescent).
Stranger anxiety begins around 6 to 8 months; separation anxiety peaks in toddlers.
Red flags: no words by 16 months, no two-word phrases by 24 months, not walking by 18 months, hand preference before 12 months, or any regression.

Priority nursing actions

Ask about parental concerns and observe the child at every well visit (developmental surveillance).
Use a standardized developmental screening tool at 9, 18 and 30 months, and autism screening at 18 and 24 months.
Compare findings with expected milestones, using corrected age for preterm infants.
Refer promptly for a failed screen, a missed red-flag milestone or any loss of skills; do not wait to rescreen.
Plan care and teaching by developmental stage, and give anticipatory safety guidance for the next stage.

Numbers to know

Age	Motor	Language and social
2 months	Lifts head when prone	Social smile, coos
6 months	Rolls back to abdomen; no head lag	Babbles; birth weight doubled
9 months	Sits steadily, crawls, pulls to stand; crude pincer grasp	Plays peekaboo; stranger anxiety
12 to 15 months	Cruises at 12 months; walks alone by 15 months	A few words besides mama and dada; birth weight tripled
18 months	Runs clumsily; tower of 3 to 4 blocks	10 or more words; points to body parts
2 years	Walks up and down stairs, two feet per step; tower of 6 to 7 blocks	Two-word phrases, about 300 words; parallel play
3 years	Rides a tricycle; copies a circle	3- to 4-word sentences; begins associative play
4 years	Hops on one foot; copies a square	4- to 5-word sentences; tells stories

Common exam traps

Choosing to call a 2-year-old's play beside, but not with, peers a social delay: wrong because parallel play is expected for toddlers.
Choosing to rescreen in 6 months after a positive screen or lost words: wrong because delayed referral delays early intervention.
Choosing chronological age for a preterm infant: wrong because it labels expected development as delay; subtract the weeks born early.
Choosing reassurance for a strong hand preference before 12 months: wrong because it suggests weakness of the other arm, as in cerebral palsy.

What to teach

Milestones occur within a range; report any loss of words or skills right away rather than waiting for the next visit.
Talk, read and play with the child every day; avoid screen media other than video chatting before 18 months, and limit it to 1 hour a day of quality programming at 2 to 5 years.
With toddlers, offer limited choices, keep routines and stay calm through tantrums without giving in.
Childproof ahead of the next milestone: before rolling, crawling, pulling to stand and climbing.

Try 2 NCLEX-style questions on this topic

From the NCLEXPace question bank. Pick your answers, then check them inside NCLEXPace.

Question 1 · QID 729DB9AE

The nurse assesses a 24-month-old at a well-child visit. For each finding, indicate whether it is expected or a red flag requiring follow-up.

For each finding at 24 months, identify whether it is expected or a red flag requiring follow-up.

	Expected	Red flag
Has only a few single words and no word combinations
Cannot follow a simple one-step direction, such as "give me the ball"
Runs well and walks up and down stairs one step at a time
Uses 2-word phrases such as "more juice"

Question 2 · QID 2539FCF1

A parent is concerned that their 2-year-old plays near other children at daycare but does not share toys or play cooperatively with them. Which response by the nurse is most appropriate?

Select the best answer.

A. "Begin structured sharing practice at daycare and require your child to take turns with each toy so cooperative play develops on schedule."
B. "Playing beside other children without joining their games suggests delayed peer interaction and should prompt a formal social-development assessment."
C. "Increase the amount of group play at daycare because children this age usually become cooperative once they have enough repeated peer exposure."
D. "Parallel play, playing near but not directly with peers, is expected at this age."

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More tips on Pediatrics

Type 1 Diabetes in Children: Lows, Sick Days and DKATreat hypoglycemia in children safely, keep basal insulin on sick days, spot cerebral edema in DKA, and match self-care to the child's age.Immunizations: Schedule Principles and ContraindicationsKnow which vaccines are live, the true contraindications versus the false ones, the timing rules, and safe administration and teaching.Croup vs Epiglottitis: Tell Them Apart FastSeparate viral croup from bacterial epiglottitis by onset, cough, drooling and posture, and know why the throat is never examined in epiglottitis.

Sources

Hockenberry MJ, Duffy EA, Gibbs KD. Wong's Nursing Care of Infants and Children. 12th ed. Elsevier; 2024.
Lipkin PH, Macias MM; Council on Children With Disabilities, Section on Developmental and Behavioral Pediatrics. Promoting Optimal Development: Identifying Infants and Young Children With Developmental Disorders Through Developmental Surveillance and Screening. Pediatrics. 2020;145(1):e20193449.
Zubler JM, Wiggins LD, Macias MM, et al. Evidence-Informed Milestones for Developmental Surveillance Tools. Pediatrics. 2022;149(3):e2021052138.

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