Ponderal index (PI)
A ratio of body weight to length used as an indicator of asymmetric fetal growth status. The ponderal index assumes that length is relatively unaffected by changes in nutritional status, so a low PI may suggest disproportionate wasting in relation to length.
Formula
PI = [birth weight (g) × 100] ÷ [birth length (cm)]³
PI = [birth weight (g) × 100] ÷ [birth length (cm)]³
Normal range: 2.32 to 2.85 g/cm³
References