General Pediatrics and Growth & Development
Core concepts
Growth is the most sensitive index of child health. Know the mechanics of plotting and interpreting weight, length/height, head circumference, and BMI on standard charts, and the difference between a cross-sectional single point and a longitudinal velocity. Understand normal milestones by domain (gross motor, fine motor, language, social) with the classic red flags: no social smile by 2 months, no head control by 4 months, no sitting by 9 months, no words by 16–18 months, no two-word phrases by 24 months. Distinguish global delay from isolated delay and know when to screen for autism, hearing loss, and vision. Understand the physiology of failure to thrive (inadequate intake, malabsorption, increased losses/needs) and the difference between constitutional growth delay and familial short stature using bone age and mid-parental height.
Traps
- Confusing regression (loss of milestones) with slow acquisition - regression mandates urgent neuro workup.
- Forgetting that prematurity shifts milestone expectations (correct until ~2 years).
- Misreading a single low weight as failure to thrive when length and head circumference are preserved and velocity is normal.
- Missing that head circumference crossing centiles upward suggests hydrocephalus, downward suggests microcephaly or a growing brain insult.
Worked example / rule of thumb
Mid-parental height: boys = (father + mother + 13)/2 cm; girls = (father + mother − 13)/2 cm. Target range ±8.5 cm. If a child's height is below the target range with a delayed bone age, think constitutional delay; if bone age matches chronological age and the child is short, think familial or pathologic short stature and screen for chronic disease, celiac, hypothyroidism, and growth hormone deficiency. Rule of thumb: a child growing along a centile is usually well; a child crossing centiles downward deserves investigation.