Femur Length (FL)

Data sources

• INTERGROWTH-21st: Centile and z-score tables for FL.
• NICHD: Race/ethnicity-stratified percentiles.

Mapping strategy

• FL is a strong predictor of gestational age when combined with head circumference.
• Very short FL (<5th percentile) may indicate skeletal dysplasia or growth restriction.

Planned extensions

• Add direct z-score computation and cross-standard comparisons.