What is the growth percentile for a 15-year-old female, weighing 41.4 kg and measuring 134.8 cm in height, according to the UK WHO (World Health Organization) growth chart, and what is her corresponding BMI (Body Mass Index) and BMI centile?

Growth Assessment for 15-Year-Old Female

This 15-year-old female with weight 41.4 kg and height 134.8 cm has a BMI of 22.7 kg/m², which falls at approximately the 50th centile for BMI, but her height is severely compromised at approximately the 0.4th centile (well below the 2nd centile), indicating significant short stature that requires immediate evaluation for underlying pathology. 1

BMI Calculation and Interpretation

• BMI = 22.7 kg/m² (calculated as 41.4 kg ÷ [1.348 m]²)
• BMI Centile: Approximately 50th centile for a 15-year-old female according to UK-WHO growth charts 1, 2
• The BMI itself appears normal for age, falling between the 25th-75th centiles 2

Critical Height Assessment

• Height: 134.8 cm at age 15 years
• Height Centile: Below 0.4th centile (approximately -2.7 SD below the mean) 3, 2
• This represents severe short stature, as she is more than 2 standard deviations below the expected height for her age 1
• Immediate action required: Children with measurements below the 2nd centile require comprehensive evaluation for growth disorders, endocrine abnormalities (particularly growth hormone deficiency, hypothyroidism), chronic diseases, genetic syndromes (Turner syndrome in females), nutritional deficiencies, or skeletal dysplasias 1, 4

Weight Assessment

• Weight: 41.4 kg
• Weight Centile: Approximately 9th centile for age, which is low-normal but proportionate to her severely reduced height 2
• The weight-for-height relationship (reflected in the normal BMI) suggests her weight is appropriate for her actual height, though both parameters are significantly below expected values 4

Clinical Implications and Required Actions

This growth pattern is highly abnormal and demands urgent investigation:

• Plot serial measurements on UK-WHO growth charts to assess growth velocity and trajectory over time 1, 3
• Evaluate for constitutional growth delay, familial short stature, or pathological causes 4
• Screen for Turner syndrome (karyotype analysis in females with unexplained short stature) 4
• Assess thyroid function (TSH, free T4) for hypothyroidism 4
• Evaluate growth hormone axis (IGF-1, IGFBP-3, consider growth hormone stimulation testing) 4
• Review nutritional history, dietary intake patterns, and assess for malabsorption or chronic disease 1
• Obtain bone age radiograph to assess skeletal maturation 4
• Calculate mid-parental height to determine genetic height potential 4

Growth Chart Selection

• The UK transitioned to UK-WHO growth charts, which use WHO standards for ages 2 weeks to 4 years, then UK 1990 reference data extended through age 20 years 3, 2
• For a 15-year-old, the UK-WHO charts utilize UK 1990 reference data, providing nine centile curves (0.4th, 2nd, 9th, 25th, 50th, 75th, 91st, 98th, 99.6th) 2
• These charts allow precise SD score calculation using the LMS method, accounting for skewness in the distribution 2

Common Pitfalls to Avoid

• Do not reassure based on normal BMI alone - the severely reduced height indicates significant pathology requiring investigation 1
• Do not delay referral - growth potential diminishes with advancing bone age, particularly critical at age 15 when epiphyseal closure approaches 4
• Do not assume familial short stature without documentation - obtain accurate parental heights and calculate mid-parental height before attributing short stature to genetics 4
• Recognize that normal weight-for-height (BMI) can mask underlying growth failure when both parameters are proportionately reduced 4