Normal growth from fetal life through adolescence — viva

Stem

You are the paediatric registrar in a general clinic. The examiner asks you to teach normal growth, then interpret cases. [1]

Branch A — Opening physiology

Examiner: How do you explain normal linear growth across childhood? [3]

Strong answer: I use the ICP model. Infancy is largely nutrition-driven. Childhood depends on the GH–IGF-1 axis. Puberty adds sex steroids that amplify GH action and produce the spurt. Fetal growth before that depends on placenta and maternal supply. I always interpret size with velocity, not a single point. [3] [1]

Branch B — Chart choice

Examiner: Which chart and why? [1]

Strong answer: I name standard versus reference first. WHO 0–5 standards describe how children should grow under favourable conditions. CDC 2000 charts are population references. In the US recommendation set, WHO is preferred under 24 months and CDC from 2 years; WHO extremes are screened near ±2 SD. I use local UK-WHO or ANZ health-book tools when that is the service standard, and preterm tools early for ex-preterm infants. [1] [2]

Branch C — Short stature pattern

Examiner: Height is just below −2 SDS but velocity is normal and parents are short. [5]

Strong answer: That pattern fits familial short stature more than endocrine failure. I re-measure, confirm the chart, check mid-parental height, examine for disproportion and systemic disease, and avoid mega-panels if velocity and exam are reassuring. I explain the channel without shame. [5]

Branch D — Pathological short stature

Examiner: Height is below −2 SDS and the height centile is falling. [5]

Strong answer: Poor velocity is a red flag. I take a full systems and nutrition history, examine carefully, and use directed tests rather than a fixed mega-panel. Endocrine referral and consideration of GH pathways sit after first-line evaluation. ISS is only a residual label after full work-up including stimulated GH testing in consensus statements. [5] [6]

Branch E — SGA graduate

Examiner: Birth weight was below the 10th centile for gestation. [4]

Strong answer: That is an SGA birth-size label. FGR is a fetal process and is not identical. Many infants catch up; I monitor those who do not and follow international SGA consensus principles for etiology review and longer-term risk. [4]

Branch F — Safeguarding and communication

Examiner: Weight and height are both falling and stories conflict. [7]

Strong answer: I stabilise medically if needed, document facts, use trauma-informed language, and escalate safeguarding in parallel. Not every faltering case is neglect, but multi-parameter faltering with social red flags must not be ignored. [7]

Examiner traps

• Single-point diagnosis without velocity.
• Calling every 3rd-centile child ISS.
• Using the wrong chart or uncorrected prematurity.
• Blaming breastfeeding for WHO-normal infant growth.
• Missing safeguarding while debating centiles. [1] [5] [7]