Ponderal index (PI) in neonatePonderal index has been used as an indicator of fetal growth status, especially to assess assymetrical IUGR. Ponderal index can be used to indentify infants whose soft tissue mass is below normal for the stage of skeletal development. The Ponderal index is calculated by multiplying the weight in grams by 100 and then dividing it by cube of length in cm.Ponderal index = Weight (gm) x 100 / Length (cm)3A ponderal index below the 10th percentile may be used to identify IUGR infants correctly. A low neonatal ponderal index is defined as less than 1 SD below a mean 2.0. PI is usually less than 2 in assymmetric growth retarded baby and 2 or more in a baby who has either normal growth or has symmetrical growth retardation. The PI of the baby in question is PI = 200 x 100 / (50)3 = 1.6 That means the baby is having assymetic IUGR (PI < 2). Fetal ponderal index can also be calculated by USG examination and compared with neonatal PI. Fetal PI had been found to be predictor of IUGR with the sensitivity and specificity of 76.9 and 82%, respectively. If the fetal PI is less than 1SD, the fetal and neonatal well being is compromised.