Improved prediction of intrauterine growth retardation with use of multiple parameters.

Several sonographic parameters have been proposed for predicting intrauterine growth retardation (IUGR), but each has been shown to have a low positive predictive value. To predict IUGR more reliably, the authors developed a multiparameter approach based on sonographic and clinical data from 62 fetuses with IUGR and 91 normal fetuses. Logistic regression analysis revealed that the combination of sonographically estimated fetal weight, amniotic fluid volume, and maternal blood pressure status best correlates with the presence or absence of IUGR and produced an IUGR scoring system based on these three parameters. The scoring system, which has a range of 0-100, was tested on a second set of fetuses (47 with IUGR, 81 normal) to determine its performance characteristics. An IUGR score below 50 virtually excludes the diagnosis of IUGR (0.9% likelihood of IUGR, or negative predictive value of 99.1%). A score above 75 allows confident diagnosis of IUGR (positive predictive value, 82%). A score of 50-75 is equivocal, in that it is associated with an intermediate (24%) likelihood of IUGR. The IUGR score is a practical tool that can be easily used in any ultrasound facility.