Comparison of clinical versus ultrasound estimation of fetal weight.

A prospective study was conducted of the accuracy of fetal weight estimation comparing clinical and ultrasound estimation with actual birth weight in 200 Iranian pregnant women. The results showed that there was statistically significant difference between clinical estimate of fetal weight and actual birth weight, as well as between ultrasound estimation and actual birth weight. The mean error of clinical estimation was 101 g, or 32 g/kg, for a 3.2% error. The error of ultrasound in the same population was 141 g, or 45 g/kg, for a 4.5% error. Analysis of these data revealed statistically significant difference between the mean error of clinical estimation and ultrasound estimation of fetal weight. Our study indicates that the mean clinical estimate of fetal weight is equal to ultrasound for the estimation of fetal weight in our population. This has important implications for developing countries where there is a lack of technologically advanced ultrasound machines capable of performing sophisticated functions like fetal weight estimation.