Pediatrics is a unique specialty that requires understanding normal growth and development alongside disease recognition and management. Children are not simply small adults - they have distinct physiological, psychological, and social needs. This comprehensive guide covers developmental milestones, growth assessment, immunization schedules, and common pediatric conditions essential for medical students and clinicians.
Growth Assessment
Growth Parameters
Weight:
- Birth weight: 3-3.5 kg average
- Doubles by 5 months, triples by 1 year
- Gain: 25-30 g/day (0-3 months), 15-20 g/day (3-6 months)
Length/Height:
- Birth length: ~50 cm
- Increases by 50% at 1 year, doubles by 4 years
- Growth spurts: Infancy, puberty
Head Circumference:
- Birth: 35 cm average
- Increases 2 cm/month (0-3 months), 1 cm/month (3-6 months)
- Important for detecting microcephaly/macrocephaly
Use WHO and CDC growth charts for monitoring. Learn more at CDC Growth Charts.
Developmental Milestones
Gross Motor Development
- 3 months: Holds head steady, pushes up on arms when prone
- 6 months: Sits without support, rolls over
- 9 months: Crawls, pulls to stand
- 12 months: Walks with one hand held, stands alone briefly
- 18 months: Walks independently, runs stiffly
- 2 years: Runs well, kicks ball, walks up stairs
- 3 years: Pedals tricycle, alternates feet on stairs
Fine Motor Development
- 3 months: Grasps rattle placed in hand
- 6 months: Transfers objects hand to hand
- 9 months: Pincer grasp (thumb and index finger)
- 12 months: Releases object voluntarily
- 18 months: Scribbles, builds tower of 3-4 cubes
- 2 years: Tower of 6-7 cubes, imitates vertical line
- 3 years: Copies circle, uses scissors
Language Development
- 3 months: Coos, laughs
- 6 months: Babbles ("ba-ba")
- 9 months: Says "mama/dada" non-specifically
- 12 months: 1-2 words with meaning
- 18 months: 10-20 words, points to body parts
- 2 years: 50 words, 2-word phrases
- 3 years: 200+ words, 3-word sentences, asks questions
Social/Cognitive Development
- 2 months: Social smile
- 6 months: Stranger anxiety begins
- 12 months: Waves bye-bye, plays peek-a-boo
- 18 months: Separation anxiety peaks
- 2 years: Parallel play, follows 2-step commands
- 3 years: Knows name, age, gender; plays with others
For clinical examination techniques, see our Clinical Examination Guide.
Immunization Schedule
Routine Vaccines (India/WHO)
At Birth:
- BCG (Bacillus Calmette-Guérin) - Tuberculosis
- OPV 0 (Oral Polio Vaccine) - birth dose
- Hepatitis B 1
6 weeks:
- DTwP/DTaP 1 (Diphtheria, Tetanus, Pertussis)
- IPV 1 (Inactivated Polio Vaccine)
- Hib 1 (Haemophilus influenzae type b)
- Hepatitis B 2
- Rotavirus 1
- PCV 1 (Pneumococcal Conjugate Vaccine)
10 weeks, 14 weeks: Repeat doses of above vaccines
9 months: Measles-Mumps-Rubella (MMR) 1
12-15 months: PCV booster, MMR 2
16-24 months: DTwP/DTaP booster, OPV booster
For complete schedules, visit CDC Vaccine Schedules or WHO Immunization.
Common Pediatric Conditions
Respiratory Infections
Bronchiolitis:
- Most common cause: RSV (Respiratory Syncytial Virus)
- Age: <2 years, peak 2-6 months
- Symptoms: Cough, wheeze, respiratory distress
- Management: Supportive (oxygen, hydration)
Croup (Laryngotracheobronchitis):
- Cause: Parainfluenza virus
- Symptoms: Barking cough, stridor, hoarseness
- Management: Dexamethasone, nebulized epinephrine for severe cases
Gastrointestinal Conditions
Acute Gastroenteritis:
- Common causes: Rotavirus, Norovirus, E. coli
- Symptoms: Diarrhea, vomiting, dehydration
- Management: ORS (Oral Rehydration Solution), zinc supplementation
- Assess dehydration using WHO criteria
Intussusception:
- Age: 6-18 months typically
- Symptoms: Colicky pain, "currant jelly" stools, palpable mass
- Diagnosis: Ultrasound (target sign)
- Management: Air/contrast enema, surgery if unsuccessful
Infectious Diseases
Measles:
- Highly contagious, preventable by MMR vaccine
- Symptoms: Fever, cough, coryza, conjunctivitis, Koplik spots, maculopapular rash
- Complications: Pneumonia, encephalitis, death
Kawasaki Disease:
- Vasculitis affecting medium-sized arteries
- Criteria: Fever ≥5 days + 4 of: conjunctivitis, oral changes, rash, extremity changes, lymphadenopathy
- Complication: Coronary artery aneurysms
- Management: IVIG, aspirin
Hematologic Conditions
Iron Deficiency Anemia:
- Most common anemia in children
- Risk factors: Prematurity, cow's milk before 1 year, poor diet
- Treatment: Iron supplementation, dietary counseling
Nutrition
Infant Feeding
- Exclusive breastfeeding: First 6 months recommended
- Complementary feeding: Start at 6 months
- Formula feeding: If breastfeeding not possible
- Avoid cow's milk before 1 year
Nutritional Requirements
- Calories: ~100 kcal/kg/day (infants)
- Protein: 1-2 g/kg/day
- Iron: 1 mg/kg/day (especially 6-12 months)
- Vitamin D: 400 IU/day supplementation
Red Flags in Development
Refer for evaluation if:
- Not smiling by 3 months
- Not sitting by 9 months
- Not walking by 18 months
- No words by 18 months
- Loss of previously acquired skills (regression)
- Persistent head lag beyond 6 months
External Resources
Conclusion
Pediatrics requires knowledge of normal development, growth monitoring, and age-appropriate disease management. Regular practice with growth chart interpretation and milestone assessment is essential. Test your pediatric knowledge with our Question Bank and explore more topics in our blog.