Situation: A nurse at a Rural Health Unit (RHU) runs a well-child clinic for children aged 3 to 6 years before they enter school. The nurse reviews the height record of a girl at her 5-year well-child visit: Age | Height 3 years | 95.0 cm 4 years | 102.0 cm 5 years | 105.5 cm At 5 years, her height-for-age z-score is about -0.8. She has had no serious illness. How should the nurse interpret her growth?

Preschoolers normally grow about 6 to 8 cm a year. She grew 7.0 cm from 3 to 4 years but only 3.5 cm from 4 to 5 years, so her growth velocity has halved and needs evaluation for endocrine or chronic disease. Her height-for-age is still above -2 z, so she is not stunted; the falling velocity, not a single value, is the warning sign.

Interpretation of growth pattern

The key issue in this scenario is not the girl’s current height-for-age, but the change in her growth velocity over time. A single z-score can look acceptable while the rate of growth is already faltering.

From 3 to 4 years, she grew 7.0 cm (102.0 − 95.0), which is within the expected preschool gain of roughly 6–8 cm per year. However, from 4 to 5 years, she gained only 3.5 cm (105.5 − 102.0). A drop in annual height velocity to about half of the previous year’s gain is a warning sign, even when the absolute height-for-age remains above −2 z.

Her height-for-age z-score of −0.8 is still within the normal range, so she does not meet the definition of stunting. Stunting is a chronic condition reflected by a height-for-age below −2 z, and that is not present here. Key point! The problem is the falling velocity, not the single current value.

Why growth velocity matters more than one measurement

Growth is a dynamic process. A child can have a normal height today but be crossing percentiles downward because the rate of gain has slowed. In preschool-aged children, a sustained velocity below expected norms raises concern for endocrine disorders such as growth hormone deficiency or hypothyroidism, as well as chronic systemic disease, malnutrition, or psychosocial deprivation. The nurse should not reassure the family based only on the z-score.

Watch out! Do not confuse “not stunted yet” with “growing normally.” A child who is losing velocity may eventually fall below −2 z if the cause is not identified and managed.

Applying the growth phases to this case

The first five years of life are a period of relatively rapid growth, after which the rate normally slows but remains steady until puberty ^[4]. In this girl, the expected pattern would be a consistent annual gain of about 6–8 cm during the preschool years. Instead, the sharp drop from 7.0 cm to 3.5 cm represents a deceleration that is not explained by normal developmental phases at this age.

Age interval	Height gain	Interpretation
3 to 4 years	7.0 cm	Within expected 6–8 cm/year
4 to 5 years	3.5 cm	Below expected; velocity has halved
Height-for-age at 5 years	−0.8 z	Above −2 z, so not stunting

Clinical reasoning for the nurse

The most appropriate interpretation is that growth has slowed, because the past year’s gain of 3.5 cm is below the expected preschool velocity. The nurse should obtain a more detailed history, review previous measurements for trend, assess nutritional intake and systemic symptoms, and facilitate referral for further evaluation of possible endocrine or chronic disease. Relying on the total gain over two years (10.5 cm) masks the recent deceleration and can delay diagnosis.

A falling growth velocity is a more sensitive early indicator of growth failure than a single height-for-age z-score that is still within the normal range. Serial measurements plotted on a growth chart are essential for detecting this pattern before stunting develops.