growth_standards 5.4.1

A Dart implementation of various growth standards, WHO, CDC, Fenton, Intergrowth, etc.

Growth Standards for Dart & Flutter

A comprehensive, clinically accurate growth standards library for Dart and Flutter. Calculates exact Z-scores, percentiles, longitudinal growth trajectories, and WHO growth velocities with built-in SVG vector growth chart rendering. Need PNG or PDF? Convert the SVG output with any external tool (e.g. rsvg-convert, Inkscape, or a browser).

📚 Documentation: See REFERENCES.md for comprehensive scientific documentation, official references, and implementation guidelines for all growth standards.

💡 Looking for code samples? Check out the example/ directory for dedicated runnable scripts covering every growth measurement type.

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Supported Standards & Measurement Types

Standard Category	Age / Target Range	Measurement Types Supported
WHO Child Growth Standards	0 to 5 Years (0–1856d)	Weight-for-Age, Length-for-Age, Weight-for-Length, Weight-for-Height, BMI-for-Age, Head Circumference, Arm Circumference (MUAC), Subscapular Skinfold, Triceps Skinfold
WHO Growth Reference	5 to 18 Years	Height-for-Age (5-18y), Weight-for-Age (5-10y), BMI-for-Age (5-18y)
WHO Growth Velocity	0 to 2 Years	Weight Velocity, Length Velocity, Head Circumference Velocity (1, 2, 3, 4 & 6-month increments)
CDC Clinical Growth Charts	2 to 20 Years & Infant 0-36m	Weight-for-Age, Stature-for-Age, BMI-for-Age, Infant Weight, Infant Length, Infant Head Circumference, Weight-for-Stature
Fenton Preterm Standards	22 to 50 Weeks PMA	Preterm Weight-for-Age, Preterm Length-for-Age, Preterm Head Circumference-for-Age
INTERGROWTH-21st	Perinatal & Fetal	Early Pregnancy CRL Dating, Fetal CRL, Fetal AC, Fetal BPD, Fetal FL, Fetal HC, Newborn Size at Birth, Postnatal Preterm Growth

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Code Examples

1. Basic Z-Score & Percentile Calculation

import 'package:growth_standards/growth_standards.dart';

void main() {
  final dob = Date(year: 2023, month: Months.june, date: 15);
  final infantAge = Age(dob, observedDate: Date(year: 2024, month: Months.june, date: 15));

  // WHO Weight-for-Age (Boy, 1 Year Old)
  final result = GrowthStandard.who.fromBirthTo5Years.weightForAge(
    sex: Sex.male,
    age: infantAge,
    weight: Mass$Kilogram(10.2),
  );

  print('Z-Score: ${result.zScore()} SD');      // e.g. +0.5 SD
  print('Percentile: ${result.percentile()}%');  // e.g. 69.3%

  // Render directly to an SVG vector file (Z-Score or Percentile variants)
  result.saveSvg('who_weight_for_age_boy_zscore.svg');
  result.saveSvg('who_weight_for_age_boy_percentile.svg', chartMode: ChartMode.percentile);
}

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2. Longitudinal Trajectory Tracking (GrowthTrajectory)

Set patient demographics (Sex & DOB) once, then record clinical visit observations over time:

import 'package:growth_standards/growth_standards.dart';

void main() {
  // Initialize trajectory helper with child demographics ONCE
  final trajectory = GrowthTrajectory.whoWeightForAge(
    sex: Sex.female,
    dateOfBirth: Date(year: 2023, month: Months.january, date: 15),
  );

  // Append visit observations (visit date + measurement)
  trajectory.add(Date(year: 2023, month: Months.january, date: 15), Mass$Kilogram(3.2));
  trajectory.add(Date(year: 2023, month: Months.april, date: 15), Mass$Kilogram(5.8));
  trajectory.add(Date(year: 2023, month: Months.july, date: 15), Mass$Kilogram(7.4));
  trajectory.add(Date(year: 2024, month: Months.january, date: 15), Mass$Kilogram(9.5));

  // Access trajectory analytics
  print('Total Visits Tracked: ${trajectory.length}');
  print('Z-Scores Over Time: ${trajectory.zScores}');
  print('Percentiles Over Time: ${trajectory.percentiles}');
  print('Latest Result: ${trajectory.latestResult?.zScore()} SD');

  // Export full multi-point trajectory growth chart graphic
  trajectory.saveSvg('patient_trajectory_zscore.svg');
  trajectory.saveSvg('patient_trajectory_percentile.svg', chartMode: ChartMode.percentile);
}

Trajectory Constructors Available Across Standards

Standard	Trajectory Constructors Available
WHO 0–5y	GrowthTrajectory.whoWeightForAge, whoLengthForAge, whoWeightForLength, whoWeightForHeight, whoBmiForAge, whoHeadCircumferenceForAge, whoArmCircumferenceForAge, whoSubscapularSkinfoldForAge, whoTricepsSkinfoldForAge
WHO 5–18y	GrowthTrajectory.who5To18HeightForAge, who5To10WeightForAge, who5To18BmiForAge
CDC 2–20y	GrowthTrajectory.cdcWeightForAge, cdcStatureForAge, cdcBmiForAge
CDC 0–36m	GrowthTrajectory.cdcInfantWeightForAge, cdcInfantLengthForAge, cdcInfantHeadCircumferenceForAge
Fenton Preterm	GrowthTrajectory.fentonWeightForAge, fentonLengthForAge, fentonHeadCircumferenceForAge
INTERGROWTH	GrowthTrajectory.intergrowthPretermPostnatalWeight, intergrowthPretermPostnatalLength, intergrowthPretermPostnatalHeadCircumference, intergrowthFetalAbdominalCircumference, intergrowthFetalFemurLength, intergrowthFetalHeadCircumference, intergrowthFetalBiparietalDiameter

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3. WHO Growth Velocity Calculation & Chart Export

import 'package:growth_standards/growth_standards.dart';

void main() {
  final age = Age.byMonthsAgo(6);
  final msr1 = MassMeasurementHistory(age.dateAtMonthsAfterBirth(4), Mass$Kilogram(6.4));
  final msr2 = MassMeasurementHistory(age.dateAtMonthsAfterBirth(6), Mass$Kilogram(7.9));

  final velocityResult = GrowthStandard.who.fromBirthTo5Years.weightVelocityForAge(
    sex: Sex.male,
    age: age,
    pastMeasurement: [msr1, msr2],
  );

  // Render velocity chart graphic
  velocityResult.saveSvg('who_weight_velocity.svg');
}

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4. Customizing Growth Chart Styling & Options

import 'package:growth_standards/growth_standards.dart';

void main() {
  final cdcWfa = GrowthStandard.cdc.from2YearsAndAbove.weightForAge(
    sex: Sex.female,
    age: Age(Date(year: 2016, month: Months.june, date: 1), observedDate: Date(year: 2024, month: Months.june, date: 1)),
    weight: Mass$Kilogram(26.5),
  );

  // Customize chart display mode and theme
  final config = GrowthChartConfig(
    displayMode: GrowthChartDisplayMode.percentile, // Render Percentiles instead of Z-scores
    title: 'CDC Weight-for-Age Clinical Record (Girl, 8 Years)',
    patientInfo: 'Patient: Jane Doe | ID: 12345',
    watermarkText: 'CONFIDENTIAL',
    showGridLines: true,
    showLegend: true,
    showResultCallout: true,
    theme: GrowthChartTheme.girl(),
  );

  cdcWfa.saveSvg('custom_cdc_chart.svg', config: config);
}

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Runnable Example Scripts

Browse the example/ folder for dedicated runnable examples for every growth standard:

• example/who_standards_example.dart: All 12 WHO 0-5y & 5-18y growth standards.
• example/who_velocity_example.dart: WHO Weight, Length, and Head Circumference velocity gains.
• example/cdc_standards_example.dart: CDC 2-20y & infant 0-36m growth charts.
• example/fenton_preterm_example.dart: Fenton 2025 Preterm growth charts (22-50w PMA).
• example/intergrowth_fetal_example.dart: INTERGROWTH-21st fetal ultrasound & dating standards.
• example/growth_trajectory_example.dart: Longitudinal child growth tracking with GrowthTrajectory.
• example/example.dart: High-level package summary example.

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Community & Support 🌟

I'm passionate about creating high-quality open-source medical tools for Dart and Flutter. Your support helps maintain and expand this package!

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