What is the initial workup and management for a 1-year-old with short stature?

Initial Workup for Short Stature in a 1-Year-Old

Begin with a comprehensive growth assessment including detailed birth measurements, family history with parental heights, serial growth measurements plotted on WHO growth charts, and a thorough physical examination to identify dysmorphic features or body disproportion—this will guide whether the short stature is a normal variant or requires further investigation. 1

Essential Historical Information

• Document birth parameters (weight, length, head circumference) to identify intrauterine growth restriction, as this suggests different etiologies than postnatal-onset short stature 2
• Obtain parental heights to calculate midparental height and assess genetic potential for growth 1
• Review parental childhood growth patterns and timing of puberty, as constitutional delay and familial short stature are often inherited 2, 3
• Assess growth velocity over the past 4-6 months if previous measurements are available—crossing centile lines at this age may be normal as large infants establish their genetic growth curve, but persistent deceleration warrants investigation 2, 3

Critical Physical Examination Findings

• Evaluate body proportions (sitting height to standing height ratio) to distinguish proportionate from disproportionate short stature 2, 1
• Document dysmorphic features including facial features, limb abnormalities, and any major or minor malformations that suggest chromosomal abnormalities or recognizable syndromes 2
• Assess developmental milestones as developmental delay combined with short stature increases likelihood of genetic syndromes 2

Initial Laboratory and Radiologic Workup

For Proportionate Short Stature Without Dysmorphic Features:

• Bone age assessment (left wrist radiograph) to determine growth potential and differentiate constitutional delay from pathologic causes 1, 4
• Basic screening labs: complete blood count, comprehensive metabolic panel, thyroid function tests to rule out hypothyroidism and chronic disease 4
• Consider chromosomal analysis, particularly in girls to rule out Turner syndrome, which is the most common pathologic diagnosis in genetic evaluations of short stature 1, 4

For Disproportionate Short Stature:

• Skeletal survey is mandatory including AP and lateral skull, entire spine, chest with ribs, pelvis, long bones, hands, feet, and lateral ankle/knee views 2
• Note: In mild skeletal dysplasias, the skeletal survey at 1 year may not be diagnostic and periodic reevaluation will be necessary; conversely, some conditions like chondrodysplasia punctata may be missed if radiographs are taken too late 2

For Short Stature With Dysmorphic Features or Developmental Delay:

• Chromosomal analysis (karyotype) should be performed first as it addresses mosaicism 2
• If karyotype is negative, genomic array studies (chromosomal microarray) should be considered to evaluate for copy number variants 2

Specific Considerations for a 1-Year-Old

• Intrauterine growth restriction assessment: Compare birth weight, length, and head circumference to determine if short stature began prenatally 2
• Evaluate for "catch-up" growth: Healthy SGA infants typically complete catch-up growth by age 2 years; failure to demonstrate catch-up by this age warrants genetic evaluation 2
• Growth velocity is critical: At this age, normal growth velocity is approximately 10-12 cm/year; significant deviation suggests pathology 3

When to Pursue Endocrine Testing

• Growth hormone stimulation testing is indicated if there is severe growth deceleration, clinical features suggesting GH deficiency (such as hypoglycemia, micropenis in males, or midline defects), or if bone age is significantly delayed without other explanation 4
• Endocrine evaluation should include assessment for combined pituitary hormone deficiencies if there are suggestive clinical features 2

Common Pitfalls to Avoid

• Do not dismiss short stature at 1 year as "too early to evaluate"—many genetic syndromes and skeletal dysplasias are identifiable at this age, and early diagnosis impacts management 2, 5
• Do not overlook Turner syndrome in girls—even without obvious dysmorphic features, karyotype should be strongly considered 1, 4
• Do not assume familial short stature without proper evaluation—skeletal survey should be considered even in familial cases if height is more than 3 standard deviations below mean, as subtle skeletal dysplasias may be present 2
• Do not order growth hormone testing as first-line—this should only follow appropriate screening and is rarely indicated at 1 year of age unless there are specific clinical indicators 4, 5

Reassessment Strategy

• If no diagnosis is apparent after initial evaluation, periodic reassessment every 3-6 months is indicated, as the phenotype may evolve and become more recognizable with age 2
• Serial growth measurements are essential—a single measurement is insufficient; growth velocity over time is the most useful indicator 3