In utero ponderal index as a prognostic factor in the evaluation of intrauterine growth retardation.

The in utero ponderal index has become a method of estimating fetal growth. Several methods have been used in the formulation of the in utero ponderal index. In the present study, 1040 pregnant women underwent ultrasonic examination between 24 and 41 weeks of gestation, and the in utero ponderal index was determined by dividing the estimated fetal weight by the third power of the femur length, rendering a relatively constant value of 8.345 +/- 2.5 (2 SD). Fifty-one cases were defined as intrauterine growth retardation due to an estimated fetal weight lower than the tenth percentile for gestational age. The in utero ponderal index proved to be a valuable index in the prediction of fetal outcome in those cases of intrauterine growth retardation in which the in utero ponderal index was smaller than 1 SD from the average of 8.345. Fetal and neonatal well-being was clearly compromised when intrauterine growth retardation was associated with a low in utero ponderal index.