Ponderal index (PI)

A ratio of body weight to length used as an indicator of asymmetric fetal growth status . The Ponderal index makes the assumption that the length is unaffected by changes in nutritional status .

Expressed as:

PI = [birth weight (g) x 100] ÷ [birth length (cm)] 3

Normal range: 2.32 to 2.85 g/cm3

Gozal D, et al. Anthropometric measurements in a newborn population in west Africa: a reliable and simple tool for the identification of infants at risk for early postnatal morbidity. J Pediatr. 1991;118(5):800-5. PMID: 2019937