1.1 Normal Growth, Development & Growth-Chart Interpretation

Board Certified Pediatric Pharmacy Specialist BCPPS

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1 Chapter 1: Pediatric Patient Characteristics — Growth, Anthropometrics & Perinatal Exposure

1.1 Normal Growth, Development & Growth-Chart Interpretation 1.2 Anthropometrics: Body Surface Area, Dosing Weights & Maximum-Dose Caps 1.3 Medication Use in Pregnancy and Lactation

2 Chapter 2: Developmental Pharmacokinetics & Neonatal Principles

2.1 Developmental PK: Absorption, Distribution & Body Water Dynamics 2.2 Hepatic Metabolism & CYP/UGT Isoenzyme Maturation 2.3 Renal Function Maturation & Glomerular Filtration Development

3 Chapter 3: Neonatal Critical Care & Prematurity Complications

3.1 Neonatal Sepsis & Meningitis (Early-Onset vs Late-Onset Sepsis) 3.2 Respiratory Distress Syndrome, Surfactant & Bronchopulmonary Dysplasia 3.3 Patent Ductus Arteriosus, Apnea of Prematurity & Necrotizing Enterocolitis

4 Chapter 4: Pediatric Infectious Diseases — Respiratory & ENT Infections

4.1 Acute Otitis Media, Sinusitis & Pharyngitis 4.2 Pediatric Community-Acquired Pneumonia & Parapneumonic Effusion 4.3 Bronchiolitis, RSV Prevention (Nirsevimab, Clesrovimab, Palivizumab) & Viral Lower Respiratory Infections

5 Chapter 5: Pediatric Infectious Diseases — Systemic, Bone & CNS Infections

5.1 Pediatric Meningitis, Encephalitis & Brain Abscess 5.2 Skin, Soft Tissue, Osteomyelitis & Septic Arthritis 5.3 Pediatric Sepsis, Febrile Neutropenia & Central Line-Associated Bloodstream Infections

6 Chapter 6: Pediatric Pulmonary Medicine — Asthma & Status Asthmaticus

6.1 Chronic Pediatric Asthma Assessment & Stepwise Outpatient Pharmacotherapy 6.2 Status Asthmaticus & Acute Exacerbation Pharmacotherapy in ED/PICU 6.3 Aerosol Drug Delivery, Spacers & Specialized Inhalation Devices

7 Chapter 7: Cystic Fibrosis & Chronic Pediatric Respiratory Disorders

7.1 Pathophysiology, Diagnosis & Airway Clearance in Cystic Fibrosis 7.2 CFTR Modulator Therapies & Monitoring 7.3 CF Pulmonary Exacerbations, Chronic Infection Management & Comorbidities

8 Chapter 8: Pediatric Cardiology & Hemodynamics

8.1 Congenital Heart Defects & Ductal-Dependent Lesions 8.2 Pediatric Heart Failure & Cardiomyopathies 8.3 Pediatric Arrhythmias & Syncope Management

9 Chapter 9: Pediatric Resuscitation, Shock & Critical Care Support

9.1 PALS Resuscitation Algorithms & Cardiac Arrest Pharmacotherapy 9.2 Pediatric Shock States & Vasoactive / Inotropic Selection 9.3 Extracorporeal Membrane Oxygenation (ECMO) & Critical Care PK

10 Chapter 10: Pediatric Neurology & Psychiatric Disorders

10.1 Neonatal Seizures & Pediatric Status Epilepticus 10.2 Pediatric Epilepsy Syndromes & Maintenance Anticonvulsants 10.3 Attention-Deficit/Hyperactivity Disorder (ADHD) & Pediatric Mood Disorders

11 Chapter 11: Pediatric Endocrinology & Metabolic Disorders

11.1 Pediatric Type 1 Diabetes Mellitus Management & Insulin Technologies 11.2 Diabetic Ketoacidosis (DKA) Protocols & Cerebral Edema Prevention 11.3 Growth Hormone, Pubertal Disorders & Congenital Adrenal Hyperplasia

12 Chapter 12: Pediatric Hematology, Oncology & Supportive Care

12.1 Sickle Cell Disease: Vaso-occlusive Crises & Disease-Modifying Therapies 12.2 Pediatric Acute Lymphoblastic Leukemia (ALL) & Chemotherapy Toxicities 12.3 Oncologic Emergencies: Tumor Lysis Syndrome & Supportive Care

13 Chapter 13: Pediatric Medication Safety & Error Prevention

13.1 High-Alert Pediatric Medications & Ten-Fold Dosing Calculation Traps 13.2 Smart Infusion Pumps & Dose Error Reduction Systems (DERS) 13.3 Medication Reconciliation & Pediatric Care Transitions

14 Chapter 14: Pediatric Compounding & Formulation Technology

14.1 Non-Sterile Compounding (USP <795>) & Liquid Formulations 14.2 Sterile Compounding (USP <797>) & Micro-Dosing Considerations 14.3 Hazardous Drug Handling (USP <800>) & Excipient Toxicities

15 Chapter 15: Fluids, Electrolytes & Clinical Nutrition Support

15.1 Fluid Requirements, Dehydration Assessment & Maintenance Therapy 15.2 Electrolyte Disturbances: Sodium, Potassium & Calcium Management 15.3 Pediatric & Neonatal Parenteral Nutrition (PN) Formulation

16 Chapter 16: Pediatric Pain Management, Sedation & Delirium

16.1 Age-Specific Pain Assessment Tools & Analgesic Selection 16.2 Procedural Sedation & Rapid Sequence Intubation in Children 16.3 PICU Delirium, Iatrogenic Withdrawal & Weaning Strategies

17 Chapter 17: Biostatistics & Study Design in Pediatric Research

17.1 Observational vs Experimental Pediatric Study Designs 17.2 Biostatistical Testing, Power & Sample Size in Small Pediatric Cohorts 17.3 Diagnostic Testing, Sensitivity, Specificity & Predictive Values

18 Chapter 18: Pediatric Evidence Appraisal, Regulatory Framework & Ethics

18.1 Pediatric Drug Legislation: BPCA, PREA & Labeling Nuances 18.2 Institutional Review Boards (IRB), Assent & Informed Consent in Minors 18.3 Evaluating Clinical Practice Guidelines & Formulating Off-Label Recommendations

19 Chapter 19: Pediatric Education, Health Literacy & Communication

19.1 Caregiver Health Literacy & Pediatric Medication Adherence 19.2 Interprofessional Education & Clinical Teaching Strategies 19.3 Developing Age-Appropriate Patient Educational Materials

20 Chapter 20: Pediatric Immunizations & Public Health Advocacy

20.1 ACIP Pediatric Immunization Schedule: Routine Childhood Vaccines 20.2 Adolescent Immunizations, Vaccine Hesitancy & Catch-Up Schedules 20.3 Pediatric Public Health Disparities & Special Population Advocacy

21 Chapter 21: Pediatric Practice Management — Laboratory Stewardship, Pharmacoeconomics & Informatics

21.1 Pediatric Laboratory Practices: Blood Conservation, Sampling Timing & Age-Specific Reference Intervals 21.2 Pharmacoeconomics, Formulary Management & Cost-Containment in Pediatrics 21.3 Clinical Informatics, CPOE Decision Support & Drug Shortage Management

1.1 Normal Growth, Development & Growth-Chart Interpretation

Key Takeaways Explain This Topic AI

The WHO growth standards are used from birth to age 24 months and the CDC growth charts from age 2 years onward; preterm infants are plotted on a preterm chart such as Fenton until about 50 weeks post-menstrual age and thereafter on corrected age, conventionally through 24 months for weight, 18 months for head circumference, and up to 36 to 40 months for length.

Term infants lose 5% to 10% of birth weight in the first days of life and regain it by 10 to 14 days, double birth weight by 4 to 6 months, triple it by 12 months, and grow about 25 cm in length and 12 cm in head circumference during the first year.

CDC BMI-for-age categories are underweight below the 5th percentile, healthy weight 5th to below 85th, overweight 85th to below 95th, class 1 obesity from the 95th percentile to below 120% of it, class 2 severe obesity at 120% to below 140% of the 95th percentile or BMI 35 kg/m2, and class 3 at 140% or BMI 40 kg/m2, with the December 2022 CDC extended charts providing the curves needed to plot above the 97th percentile.

Crossing two or more major percentile channels downward, or weight-for-length or BMI below the 5th percentile, defines faltering growth and should trigger a medication review for appetite-suppressing stimulants, growth-suppressing inhaled corticosteroids, and drug-induced malabsorption.

Sexual Maturity Rating (Tanner) stage 2 marks the onset of puberty and the point at which body composition, hepatic enzyme activity, and renal clearance begin diverging by sex, so a child at the same weight may need a different mg/kg dose before and after this transition.

Last updated: September 2026

1.1 Normal Growth, Development & Growth-Chart Interpretation

A pediatric pharmacist reads a growth chart the way an adult pharmacist reads a serum creatinine trend: it is a longitudinal physiologic signal, not a single data point. Almost every pediatric dose is anchored to weight, length, or body surface area, so the accuracy of a dose depends on the accuracy and the interpretation of an anthropometric measurement. Growth data also serve as a pharmacovigilance instrument — inhaled corticosteroids, stimulants, systemic glucocorticoids, and several antiretrovirals all announce toxicity as a change in growth trajectory long before a laboratory value moves.

Growth refers to a measurable increase in body size. Development refers to the progressive acquisition of function — motor, cognitive, language, and social. The two are tracked separately and have different pharmacy consequences: growth drives the dose, development drives the dosage form and the device.

Which Chart, and When

Population Chart Range Notes

Birth to 24 months (term) WHO Growth Standards 0–24 mo Prescriptive : describes how healthy, predominantly breastfed children should grow. CDC and AAP recommend these below age 2.

2 through 19 years CDC Growth Charts 2–20 yr Descriptive : derived from US survey data (NHANES). Includes BMI-for-age.

BMI above the 97th percentile CDC Extended BMI-for-age Charts (released December 2022) 2–20 yr The 2000 charts flatten above the 95th percentile and cannot distinguish a child at the 96th from one at the 99.9th. The extended charts add the 98th, 99th, 99.9th, and 99.99th curves and plot BMI to 60 kg/m².

Preterm infants Fenton (or INTERGROWTH-21st) preterm charts 22–50 wk PMA Plotted by post-menstrual age until roughly 50 weeks PMA, then transitioned to the WHO chart using corrected age .

Down syndrome, Turner syndrome, achondroplasia, cerebral palsy Syndrome-specific charts varies Used alongside , never instead of, the standard chart.

Important

The chart switch at age 2 is not cosmetic. WHO standards describe a breastfed reference population that gains weight more slowly after 3 months than the CDC descriptive population. A toddler who appears to be "dropping percentiles" across the 24-month transition may simply have moved from one reference population to another. Confirm the chart before concluding that growth has faltered.

Correcting for Prematurity

Corrected (adjusted) age = chronological age − (40 weeks − gestational age at birth). Conventional correction windows are:

Head circumference: correct through 18 months
Weight: correct through 24 months
Length/height: correct through 36 to 40 months

An infant born at 28 weeks who is now 9 months old chronologically has a corrected age of 9 months − 12 weeks = 6 months . Plotting that infant at 9 months manufactures a false diagnosis of growth failure and can trigger an unnecessary nutrition or endocrine workup.

Growth Velocity Benchmarks Worth Memorizing FIRST YEAR OF LIFE — EXPECTED TRAJECTORY

WEIGHT Birth ........ physiologic loss of 5-10% over 3-5 days
Day 10-14 .... back to birth weight
Month 4-6 .... DOUBLE birth weight
Month 12 ..... TRIPLE birth weight
Month 24 ..... QUADRUPLE birth weight

DAILY 0-3 mo ....... 20-30 g/day
GAIN 3-6 mo ....... 15-20 g/day
6-12 mo ...... 10-15 g/day

LENGTH Birth ~50 cm -> ~75 cm at 12 months (+50%)
Doubles birth length by ~4 years

HEAD Birth ~35 cm; +2 cm/mo (mo 1-3), +1 cm/mo (mo 4-6),
CIRCUM. +0.5 cm/mo (mo 7-12) => ~47 cm at 12 months

After infancy, growth slows to roughly 2 kg and 5 to 7 cm per year through mid-childhood, then accelerates sharply at the pubertal growth spurt. Girls peak in height velocity at about 8 to 9 cm/year around Tanner stage 3; boys peak later and higher, at about 9 to 10 cm/year around Tanner stages 3 to 4.

Percentiles, Channels, and Z-Scores

A percentile states the rank of a measurement within the reference population; a z-score states how many standard deviations the measurement sits from the median. Z-scores are preferred in nutrition support and research because they remain discriminating at the extremes, where percentiles compress — the difference between the 0.1st and the 2nd percentile is large physiologically but invisible on a percentile scale.

Major percentile lines (3rd, 5th, 10th, 25th, 50th, 75th, 90th, 95th, 97th) define channels . The clinically meaningful signal is not which channel a child occupies but whether they stay in it .

BMI-for-age obesity severity (CDC, carried into the AAP 2023 obesity clinical practice guideline):

Category Threshold
Underweight BMI < < < 5th percentile
Healthy weight 5th to < < < 85th percentile
Overweight 85th to < < < 95th percentile
Obesity, class 1 95th percentile to < 120 % <120\% < 120% of the 95th percentile

Obesity, class 2 (severe) 120 % 120\% 120% to < 140 % <140\% < 140% of the 95th percentile, or BMI ≥ 35 \ge 35 ≥ 35 kg/m², whichever is lower

Obesity, class 3 ≥ 140 % \ge 140\% ≥ 140% of the 95th percentile, or BMI ≥ 40 \ge 40 ≥ 40 kg/m², whichever is lower

Faltering growth (failure to thrive): weight-for-age or weight-for-length below the 5th percentile, or a sustained downward crossing of two or more major percentile channels .

Normal channel shifts: most healthy infants shift channels once during the first 18 months as they regress toward their genetically determined trajectory. A single crossing in this window, with normal linear growth and development, is usually benign.

Red flag ordering: weight falls first, then length, then head circumference. Head circumference falling first points away from undernutrition and toward a primary neurologic or genetic cause.

Medication Review Triggered by Growth Faltering

Drug class Growth effect Pharmacist action

Stimulants (methylphenidate, amphetamines) Appetite suppression; average height deficit roughly 1–2 cm with sustained use Plot height and weight every 6 months; consider dose timing, calorie-dense evening meals, or a planned drug holiday

Inhaled corticosteroids Roughly 0.5–1 cm reduction in first-year growth velocity; small effect on adult height Stadiometer height every 3–6 months; step down to the lowest effective dose after 3 months of control

Systemic glucocorticoids Marked growth suppression, dose- and duration-dependent Push alternate-day or inhaled/topical routes; monitor for adrenal suppression

Topiramate, stimulant-class appetite suppressants Anorexia, weight loss Reassess necessity; dietitian referral

Proton pump inhibitors, orlistat, cholestyramine Micronutrient or fat-soluble vitamin malabsorption Supplement and monitor vitamins A, D, E, K

Development: What It Changes About the Prescription

Developmental stage, not age alone, determines whether a child can physically take a medication. The CDC and AAP revised the developmental-milestone checklists in February 2022 so that each listed milestone is one achieved by about 75% of children at that age, making a missed milestone a more actionable prompt for referral.

Stage Representative milestones Pharmacy consequence

Neonate/infant (0–12 mo) Head control ~4 mo; sits ~6 mo; pincer grasp ~9 mo Oral liquids only , given by oral syringe into the buccal pocket. No honey before 12 months (infant botulism). Hyperosmolar liquids risk necrotizing enterocolitis in preterm infants.

Toddler (1–3 yr) Walks ~12 mo; two-word phrases ~24 mo; negativism peaks Liquids and orodispersible or chewable forms from about age 2. Expect refusal; taste-masking and caregiver coaching matter more than potency.

Preschool (3–5 yr) Magical thinking; fears bodily harm Most children cannot reliably swallow intact tablets before about 6 years , though structured pill-swallowing training succeeds in many from age 4. Metered-dose inhaler requires a valved holding chamber with a face mask .

School age (6–11 yr) Concrete operational reasoning; wants to participate Tablets and capsules usually feasible. Spacer with mouthpiece replaces the mask (about age 4–5). Dry powder inhalers require sustained high inspiratory flow and are generally reserved for age 5 to 6 and older .

Adolescent (12–18 yr) Abstract reasoning; autonomy-seeking; risk-taking Counsel the adolescent directly, confidentially where law allows. Adherence, not formulation, becomes the rate-limiting problem.

Sexual Maturity Rating and Its Pharmacokinetic Consequences

Tanner (Sexual Maturity Rating) staging runs 1 through 5 for breast/genital development and pubic hair.

SMR 1: prepubertal.

SMR 2: onset of puberty — breast budding in girls (average age about 10–11 years) and testicular volume above 4 mL in boys (average about 11–12 years).

SMR 5: adult.

Puberty is a pharmacokinetic inflection point. Lean body mass and total body water rise steeply in boys while fat mass rises in girls, so volumes of distribution for hydrophilic and lipophilic drugs diverge by sex for the first time. CYP3A4 and CYP1A2 activity, which exceed adult levels through childhood on a per-kilogram basis, decline toward adult values. Insulin requirements in type 1 diabetes surge to 1.0 to 1.5 units/kg/day at SMR 2 through 4 and fall again once linear growth stops. Appearance of SMR 2 changes before age 8 in girls or age 9 in boys defines precocious puberty and triggers an evaluation, not a dose adjustment.

Practice Pearls & BCPPS Exam Traps

Exam Trap 1: A 26-week preterm infant at 4 months chronological age plotted on the WHO chart appears far below the 3rd percentile. The correct action is to correct for prematurity , not to escalate nutrition support.

Exam Trap 2: Length is measured recumbent below age 2 and standing height from age 2 onward using a wall-mounted stadiometer. Recumbent length exceeds standing height by roughly 0.7 cm; switching methods without switching charts manufactures an artificial drop in the growth curve.

Exam Trap 3: Weight-for-length, not BMI, is the correct adiposity index below age 2. BMI-for-age is only validated from age 2.

Board Rule: Before attributing growth faltering in a child with asthma to the disease, confirm that the inhaled corticosteroid is at the lowest effective step, that the child is using a valved holding chamber, and that height is measured by stadiometer rather than estimated.