anthro (Python)

WHO 2006 Child Growth Standards — z-scores and classifications for 6 indicators.

Python port of the JavaScript library @flame-cai/anthro, sharing the same WHO LMS tables, formula, and output schema.

Website: https://flame-cai.github.io/anthro
PyPI: https://pypi.org/project/anthro
npm: https://www.npmjs.com/package/@flame-cai/anthro

Installation

pip install anthro

Quick start

from anthro import compute, batch

# Single child — by date of birth
result = compute({
    'sex':       'female',
    'dob':       '2024-01-15',
    'measured':  '2025-01-15',
    'weight_kg': 7.0,
    'height_cm': 64.0,
    'muac_mm':   136,
})
print(result['z_lhfa'])          # -2.7901
print(result['lhfa'])            # 'Moderately stunted'
print(result['wfa'])             # 'Normal'
print(result['muac_threshold'])  # 'Normal'

# By age in days
result = compute({'sex': 'm', 'age_days': 365, 'weight_kg': 9.5, 'height_cm': 75.2})

# Month mode
result = compute({'sex': 'f', 'age_months': 12, 'weight_kg': 9.0, 'height_cm': 74.5, 'mode': 'month'})

# Batch
results = batch([
    {'sex': 'm', 'age_days': 200, 'weight_kg': 6.8, 'height_cm': 63.0},
    {'sex': 'f', 'age_days': 400, 'weight_kg': 8.2, 'height_cm': 75.0},
])

API

compute(params) → dict

Missing inputs return a descriptive string (not None) for the affected indicators — all other indicators are still computed.

Return dict keys

mode, sex, age_days, age_months, weight_kg, height_cm_raw, height_cm_adj, muac_mm, bmi_val, measure, measure_correction, z_lhfa, z_wfa, z_wflh, z_bmi, z_acfa, flag_lhfa, flag_wfa, flag_wflh, flag_bmi, flag_acfa, muac_threshold, acfa, bmi, lhfa, wfa, wflh, errors, warnings

batch(rows, default_mode='day') → list[dict]

Low-level helpers

from anthro import lms_z, age_days, months_to_days, classify

z = lms_z(X=9.5, L=0.1, M=10.0, S=0.12)
d = age_days('2022-01-01', '2023-01-01')  # → 365
classify.muac(110)     # → 'SAM'
classify.zscore(-2.5)  # → 'MAM'

Table sources

Tables are shared from the repository's data/ directory — no duplication.

• Day-indexed (default): extracted from the R package anthro v1.1.0 (WHO-maintained, CRAN) — the same tables used by WHO igrowup SAS/SPSS/Stata software.
• Month-indexed: WHO 2006 published monthly supplementary tables.

References

• WHO MGRS (2006). WHO Child Growth Standards. Geneva: WHO. ISBN 924154693X
• Formula: Restricted LMS + SD23 adjustment — WHO (2006) §5.2
• Cut-points: WHO (2009). ISBN 9789241598163