A newborn has weight 2000 g and length 50 cm. What is the Ponderal index of this child?
Ponderal index (PI), which is calculated using the following formula: PI = Bihweight x 1000/(crown-heel length)^3 Therefore, PI = 20001000/(50)3 = 1.6 A normal index at 28 weeks is 1.8. This value increases by 0.2 every 4 weeks to reach 2.4 at 40 weeks. Asymmetric IUGR infants will have a low ponderal index (ie, they will be long, lightweight infants), whereas small normal infants will have a normal ponderal index. Ref: Rahimian J., Varner M.W. (2007). Chapter 16. Dispropoionate Fetal Growth. In A.H. DeCherney, L. Nathan (Eds), CURRENT Diagnosis & Treatment Obstetrics & Gynecology, 10e.
1
1.6
2.2
2.6