Pead Series · Week 2
Year 4 MBChB · Paediatrics & Child Health · MKU
Learning objectives
By the end of this topic, you should be able to:
- Distinguish growth from development and explain the factors that influence each.
- Measure and interpret weight, length/height, head circumference and other key anthropometric indicators.
- Use age- and sex-appropriate growth charts and recognise faltering growth, overweight and stunting.
- Describe important developmental milestones and assess the major developmental domains.
- Recognise developmental red flags and explain the first steps in assessment and referral.
- Explain adolescent growth, puberty and the value of longitudinal measurements.
1. The basic idea
Growth is a quantitative increase in body size. It can be measured: weight, length/height, head circumference and body proportions.
Development is the progressive acquisition of skills and function as the nervous system and other body systems mature. Examples include smiling, sitting, walking, speaking, solving problems and interacting socially.
Maturation is the biological process through which organs and abilities become functionally mature.
A child may grow well physically but have a developmental delay, or have a disability while growing normally. Always assess growth and development separately.
2. Factors affecting growth and development
- Genetic factors: parental height, inherited conditions and constitutional growth patterns.
- Nutrition: energy, protein and micronutrients; feeding difficulty can affect both weight gain and development.
- Prenatal factors: maternal nutrition and illness, placental function, alcohol or other harmful exposures, and prematurity.
- Chronic disease: cardiac, respiratory, renal, gastrointestinal, endocrine and chronic infectious diseases.
- Hormones: growth hormone, thyroid hormone, insulin and sex hormones.
- Psychosocial environment: caregiver interaction, stimulation, safety, neglect, stress and opportunities to play and learn.
- Social determinants: household food security, poverty, sanitation, access to healthcare and education.
- Prematurity: milestones should generally be interpreted using corrected age during the first two years for children born preterm, while also considering the child's clinical context and local guidance.
3. How to assess growth
A. History
Ask about:
- Birth weight, gestational age, birth complications and neonatal illness.
- Breastfeeding, complementary feeding, meal frequency, appetite and dietary diversity.
- Vomiting, diarrhoea, swallowing problems, recurrent infections and symptoms of chronic disease.
- Developmental progress, loss of skills, sleep, activity and behaviour.
- Previous measurements and whether the child has crossed growth-chart centile or z-score lines.
- Family heights, pubertal timing and relevant inherited conditions.
- Housing, food availability, caregiver concerns and barriers to care.
B. Measurements
Weight
- Use a calibrated scale on a firm, level surface.
- Weigh infants on an infant scale; older children can use a standing scale.
- Remove heavy clothing and shoes where practical. Record units and measurement date.
- Repeat an unexpected measurement before interpreting it.
Length and height
- In children under 2 years, measure recumbent length using an infant length board, ideally with two trained people.
- From 2 years, measure standing height with a stadiometer when the child can stand correctly.
- If a child under 2 years must be measured standing, the value is usually about 0.7 cm less than recumbent length; follow the chart's measurement convention and local protocol.
Head circumference
- Use a non-stretch tape around the largest occipito-frontal circumference: above the eyebrows and ears and around the most prominent part of the occiput.
- Repeat to obtain the largest reliable measurement.
- Plot on an age- and sex-appropriate chart, particularly in infants and young children.
Mid-upper arm circumference (MUAC)
- Used mainly in children 6–59 months to screen for acute malnutrition, according to the applicable protocol.
- Measure the left upper arm at the midpoint between the shoulder tip and elbow with the arm relaxed.
- For children 6–59 months, MUAC below 115 mm indicates severe acute malnutrition; 115 to below 125 mm indicates moderate acute malnutrition in standard WHO community/clinical criteria. Bilateral pitting oedema is a danger sign of severe acute malnutrition regardless of MUAC.
- Do not use MUAC cut-offs intended for 6–59 months indiscriminately in older children.
Body mass index (BMI)
- BMI = weight in kilograms ÷ height in metres squared.
- In children, interpret BMI using age- and sex-specific charts; adult BMI cut-offs should not simply be applied to children.
C. Plot and interpret
- Select the correct chart for the child's age and sex and the measurement taken.
- Confirm the measurement technique and units.
- Plot the point accurately.
- Compare with previous points: the direction and rate of growth matter, not only today's position.
- Interpret the z-score/centile with clinical findings, feeding history, family pattern and illness.
- Record the result, explain it to the caregiver and make a follow-up plan.
A z-score describes how far a measurement is from the reference median in standard-deviation units. A z-score of 0 is the median; −2 is two standard deviations below the median.
Common WHO growth indicators
| Indicator | What it assesses | Important interpretation |
|---|---|---|
| Weight-for-age (WFA) | Weight relative to age | Low WFA indicates underweight but does not distinguish wasting from stunting |
| Length/height-for-age (L/HA) | Linear growth relative to age | Below −2 SD indicates stunting; below −3 SD indicates severe stunting |
| Weight-for-length/height (WFL/H) | Weight relative to length/height | Below −2 SD indicates wasting; below −3 SD indicates severe wasting |
| BMI-for-age | BMI relative to age and sex | Helps assess thinness and excess weight using the correct child chart |
| Head circumference-for-age | Head growth relative to age and sex | Unusually small or large values, or abnormal trajectory, need assessment |
| MUAC | Arm circumference | Screens for acute malnutrition in the relevant age group |
For WHO child growth standards, z-scores below −2 or above +2 often warrant further assessment depending on the indicator and age. Use the exact chart and national protocol; a chart is a screening and monitoring tool, not a diagnosis by itself.
4. Recognising growth problems
Underweight: low weight-for-age. It can reflect wasting, stunting or both.
Wasting: low weight-for-length/height, usually indicating recent or acute weight loss or failure to gain weight.
Stunting: low length/height-for-age, reflecting chronic or recurrent nutritional and health adversity. Consider dietary, medical and social causes.
Faltering growth: a concerning slowing of weight gain or downward crossing of the child's expected growth trajectory. Review measurements, feeding, illness and the family context rather than relying on one number alone.
Overweight/obesity: assess using BMI-for-age or weight-for-length/height on the appropriate chart. Ask about diet, activity, sleep, medicines, family history and possible endocrine or syndromic features when indicated.
Microcephaly or macrocephaly: head circumference substantially below or above the expected range, or crossing centile lines abnormally. Confirm technique and assess development, neurological signs, family head size and other clinical findings.
Red flags in growth
- Rapid weight loss, poor feeding or failure to gain weight.
- Bilateral pitting oedema, visible severe wasting or MUAC in the severe range.
- Persistent vomiting/diarrhoea, chronic cough, recurrent infection or symptoms suggesting systemic disease.
- Marked deviation from the child's previous growth trajectory.
- Head circumference crossing centile lines substantially, especially with developmental change, seizures, abnormal tone or a bulging fontanelle.
- Height far below expected family pattern, poor height velocity or disproportionate body features.
A child with acute illness or danger signs needs immediate clinical assessment; do not delay care to complete growth-chart calculations.
5. Developmental assessment
Assess the child across four broad domains:
- Gross motor: posture, head control, sitting, standing, walking, running and balance.
- Fine motor and vision: reaching, grasping, transferring objects, pincer grasp, drawing and manipulating small objects.
- Language and hearing: response to sound/name, babbling, understanding instructions, words and sentences.
- Social, emotional and adaptive skills: eye contact, social smile, interaction, play, self-feeding, dressing and independence.
Some frameworks assess cognition/problem-solving separately; include it in your assessment. Ask what the child can actually do, not only whether a caregiver thinks development is “normal.” Observe the child at play and interaction when possible.
Selected developmental milestones
Milestones are approximate ranges, not deadlines. There is normal variation; assess the overall pattern and any loss of skills.
| Approximate age | Examples of skills commonly emerging |
|---|---|
| 2 months | Social smile, reacts to loud sounds, begins to hold head up when prone |
| 4 months | Holds head steady better, brings hands to mouth, enjoys interaction and makes sounds |
| 6 months | Rolls, reaches for objects, laughs and responds to familiar people |
| 9 months | Sits without support, transfers objects, babbles repetitive sounds, responds to own name |
| 12 months | Pulls to stand or stands holding on, uses a pincer grasp, gestures and may say a meaningful word |
| 18 months | Walks independently, scribbles, uses several meaningful words, points to show interest |
| 2 years | Runs, kicks a ball, uses two-word phrases, follows simple instructions and engages in simple pretend play |
| 3 years | Pedals a tricycle or similar, uses short sentences, participates in interactive play and may copy a circle |
| 4 years | Hops on one foot or balances briefly, tells simple stories, plays with other children and draws a person with some features |
| 5 years | Hops, follows rules in simple games, tells a story and draws/writes some letters or numbers |
Use an age-specific milestone resource and local child health record for detailed milestone ranges. Never diagnose a delay from one missed milestone alone.
Corrected age for prematurity
For a child born before 37 completed weeks, corrected age is commonly calculated as:
Corrected age = chronological age − number of weeks born before 40 weeks.
Example: born at 32 weeks (8 weeks early), now 6 months chronological age: corrected age is approximately 4 months. Corrected age is commonly used when interpreting development during the first 2 years; document both ages and follow local guidance.
6. Developmental red flags
Arrange prompt assessment if a child:
- Loses previously acquired skills at any age (developmental regression).
- Has no social smile by around 3 months or very limited social interaction.
- Has poor head control by around 4 months.
- Cannot sit independently by around 9 months.
- Has no babbling or gestures by around 12 months, or does not respond to sound/name as expected.
- Has no independent walking by around 18 months.
- Has no meaningful words by around 16 months, or no spontaneous two-word phrases by 2 years.
- Has persistent asymmetry, abnormal tone, unusual movements, seizures, or concerns about vision or hearing.
- Has difficulties in multiple domains, feeding/swallowing problems or significant caregiver concern.
These are prompts for assessment, not stand-alone diagnostic criteria. Hearing impairment, visual impairment, neurological disease, autism, global developmental delay, psychosocial adversity and other causes may need consideration. Regression, seizures, acute weakness or an acutely unwell child requires urgent medical review.
7. Approach when delay is suspected
- Clarify the concern: onset, skills achieved, skills lost, progression, and caregiver observations.
- Check age and prematurity: calculate corrected age where appropriate.
- Review risks: antenatal/birth history, prematurity, neonatal encephalopathy, infections, nutrition, family history and psychosocial context.
- Assess all domains: do not focus only on speech or walking.
- Examine: growth and head circumference, dysmorphic features, vision/hearing, tone, power, reflexes, gait and neurological signs as age-appropriate.
- Check hearing and vision and assess nutrition, sleep, behaviour and caregiver-child interaction.
- Use an appropriate validated screening tool where available; screening does not replace clinical assessment.
- Refer early for developmental/paediatric assessment and early-intervention services when indicated. Do not wait for a definitive label before supporting the child.
- Investigate selectively according to history and examination; avoid indiscriminate tests.
- Document and follow up with a clear plan and safety-net advice.
8. Adolescent growth and puberty
Adolescence includes rapid linear growth, changes in body composition and sexual maturation. The timing and tempo of puberty vary.
- Plot height and weight longitudinally; calculate BMI-for-age.
- Ask about growth pattern, nutrition, exercise, chronic illness, medicines, family pubertal timing and psychosocial wellbeing.
- Puberty is assessed clinically using Tanner stages (breast development in girls; genital development in boys; pubic hair in both). Explain the examination, obtain consent/assent, ensure privacy and chaperoning according to policy.
- In girls, breast development is commonly the first visible sign of puberty; in boys, testicular enlargement is usually the first sign.
- Consider assessment for precocious or delayed puberty when development is unusually early or late for age, when progression is unusually rapid/slow, or when accompanied by other concerning features. Use current local referral criteria rather than memorising a single threshold without context.
- Provide confidential, respectful, non-judgmental care, while explaining safeguarding limits.
9. Common OSCE mistakes
- Weighing or measuring without checking equipment or technique.
- Recording a number but not plotting it.
- Using weight-for-age alone to diagnose wasting or stunting.
- Comparing a child with adult BMI cut-offs.
- Forgetting to correct age for prematurity when appropriate.
- Asking only about walking and speech while ignoring social, fine-motor, hearing and vision skills.
- Treating a milestone table as a rigid pass/fail checklist.
- Missing regression or a caregiver's persistent concern.
- Giving reassurance without arranging review when a red flag is present.
- Failing to explain findings and the follow-up plan to the caregiver.
10. Quick OSCE checklist
- Introduce yourself, confirm identity and age, explain and obtain consent/assent.
- Ask about birth, prematurity, feeding, illness, family pattern and developmental concerns.
- Review previous growth records and developmental history.
- Measure weight, length/height and head circumference when indicated; measure MUAC in the appropriate age group.
- Plot on the correct age- and sex-specific chart.
- Interpret the trajectory and relevant z-scores, not a single measurement alone.
- Assess gross motor, fine motor/vision, language/hearing, and social/adaptive development.
- Look for red flags, regression, abnormal tone and signs of malnutrition or systemic disease.
- Summarise findings, explain them clearly and give a follow-up/referral plan.
11. Practice short-answer questions
1. Differentiate growth and development.
Growth is measurable increase in physical size; development is acquisition of skills and function across motor, language, cognitive and social domains.
2. Why is weight-for-age insufficient to diagnose wasting?
Because low weight-for-age may be due to wasting, stunting or both. Assess weight-for-length/height and length/height-for-age as well.
3. What is developmental regression?
Loss of a previously acquired skill. It is a red flag requiring prompt medical assessment.
4. Why correct age for a preterm infant?
Development is compared with the expected maturity of the infant, not only time since birth. Document chronological and corrected ages and use corrected age where recommended.
5. What do you do if a caregiver reports delayed speech?
Clarify language and social milestones, check hearing and vision, assess all developmental domains, review risk factors and examination findings, use appropriate screening, and arrange timely assessment/referral and early support.
12. Twenty exam-style MCQs
Choose the single best answer. Answers and explanations follow each question.
Q1. Which statement best defines growth?
A. Acquisition of social skills
B. Quantitative increase in body size
C. Maturation of language only
D. Ability to perform activities of daily living
Answer: B. Growth is a measurable increase in physical size, such as weight, length/height and head circumference.
Q2. A child has low weight-for-age. Which conclusion is most accurate?
A. The child definitely has wasting
B. The child definitely has stunting
C. The child is underweight, and further indicators are needed to distinguish wasting from stunting
D. The child is obese
Answer: C. Weight-for-age does not distinguish low weight due to wasting, stunting or both.
Q3. Which measure is most useful for assessing linear growth over time?
A. Head circumference alone
B. Height/length-for-age
C. Respiratory rate
D. MUAC alone
Answer: B. Length/height-for-age reflects linear growth and helps identify stunting.
Q4. In a child aged 6–59 months, a MUAC of 112 mm indicates:
A. Normal nutritional status
B. Moderate acute malnutrition only
C. Severe acute malnutrition by the standard MUAC criterion
D. Obesity
Answer: C. MUAC below 115 mm in this age group meets the standard severe acute malnutrition criterion; urgently assess and manage under local protocol.
Q5. Which finding is the clearest developmental red flag at any age?
A. A child prefers one toy
B. Loss of previously acquired words and motor skills
C. A toddler cries with strangers
D. A child varies in appetite from day to day
Answer: B. Regression is not normal variation and requires prompt assessment.
Q6. A baby was born at 32 weeks and is now 6 months old chronologically. Approximate corrected age is:
A. 2 months
B. 4 months
C. 6 months
D. 8 months
Answer: B. The baby was 8 weeks early; subtract about 2 months from chronological age.
Q7. Which is a fine-motor milestone?
A. Sitting without support
B. Walking independently
C. Using a pincer grasp to pick up a small object
D. Running
Answer: C. A pincer grasp uses the fingers for precise object handling.
Q8. Which is a gross-motor skill?
A. Babbling
B. Social smiling
C. Transferring a small object between fingers
D. Standing and walking
Answer: D. Gross motor skills involve large muscle groups, posture, balance and movement.
Q9. A child is 2 years old and has no spontaneous two-word phrases. The best next step is:
A. Ignore it until school age
B. Assess development, hearing and language environment, and arrange appropriate follow-up/referral
C. Diagnose autism from this feature alone
D. Assess only weight
Answer: B. This is a developmental concern that warrants assessment; a single feature does not establish a diagnosis.
Q10. What is the best way to interpret a growth chart?
A. Use one point only
B. Compare the child's trajectory over time and the clinical context
C. Compare every child with the tallest child in class
D. Use adult BMI cut-offs
Answer: B. Serial measurements help distinguish a stable individual pattern from faltering or abnormal growth.
Q11. Which indicator describes weight relative to length or height?
A. Weight-for-length/height
B. Height-for-age
C. Head circumference-for-age
D. Age-for-weight
Answer: A. Weight-for-length/height is used to assess thinness/wasting or excess weight in the relevant age range.
Q12. Which domain includes response to sound, babbling and understanding instructions?
A. Gross motor
B. Language and hearing
C. Fine motor only
D. Growth
Answer: B. Language assessment includes receptive and expressive communication, with hearing considered.
Q13. A child's head circumference appears unusually high. What should you do first?
A. Immediately diagnose hydrocephalus
B. Confirm the measurement and plot it on the correct chart, then assess trajectory and clinical signs
C. Ignore it if weight is normal
D. Use an adult chart
Answer: B. Check technique and trend; interpretation depends on the full clinical picture.
Q14. Which statement about developmental milestones is correct?
A. Every healthy child achieves every milestone on the same day
B. Milestones have approximate ranges, and the overall pattern matters
C. A missed milestone always proves permanent disability
D. Only speech needs to be assessed
Answer: B. There is variation, but persistent concerns or red flags require assessment.
Q15. Which factor can adversely affect both growth and development?
A. Severe or persistent undernutrition
B. Responsive caregiver interaction
C. Appropriate stimulation
D. Timely treatment of illness
Answer: A. Undernutrition can impair physical growth and brain development.
Q16. Which statement about BMI in children is correct?
A. Adult BMI cut-offs are used at all ages
B. BMI is not calculated in children
C. BMI should be interpreted using age- and sex-specific references
D. BMI alone identifies the cause of obesity
Answer: C. Children's body composition changes with age; use the appropriate chart.
Q17. A toddler is not walking independently at 18 months. The best response is:
A. Assume the child is lazy
B. Assess motor development, neurological examination, hearing/vision and other domains, and arrange appropriate referral
C. Assess only vocabulary
D. Wait indefinitely
Answer: B. Delayed walking is a reason to assess the child in context rather than label or dismiss the concern.
Q18. In boys, the first usual clinical sign of puberty is:
A. Beard growth
B. Voice breaking
C. Testicular enlargement
D. Adult muscle mass
Answer: C. Testicular enlargement is usually the earliest visible clinical sign of male puberty.
Q19. Which statement about developmental screening is correct?
A. A screening tool replaces clinical assessment
B. A normal screen rules out every developmental problem
C. Screening helps identify children who need further assessment but does not itself establish a diagnosis
D. Screening is unnecessary if the child looks healthy
Answer: C. Use screening alongside history, observation, examination and follow-up.
Q20. A caregiver is worried about a child's development, but the child appears well. What is the best approach?
A. Dismiss the concern because the child looks healthy
B. Listen carefully, clarify examples, assess development and arrange follow-up or referral when indicated
C. Wait until the next annual visit regardless of symptoms
D. Give a definitive diagnosis without assessment
Answer: B. Caregiver concerns can be important; explore them respectfully and assess systematically.
Quick answer key
1-B · 2-C · 3-B · 4-C · 5-B · 6-B · 7-C · 8-D · 9-B · 10-B · 11-A · 12-B · 13-B · 14-B · 15-A · 16-C · 17-B · 18-C · 19-C · 20-B
High-yield takeaways
- Growth = size; development = skills and function.
- Always plot accurate measurements on the correct chart and assess the trajectory.
- Weight-for-age alone cannot distinguish wasting from stunting.
- Assess gross motor, fine motor/vision, language/hearing, and social/adaptive domains.
- Correct age for prematurity when appropriate, especially in the first two years.
- Regression is a red flag at any age.
- Screening supports clinical assessment; it does not replace it.
- Early referral and intervention are preferable to waiting for a definitive diagnostic label.