Clinical and sonographic estimations of uterine weight

Over a 36 month period, all hysterectomies with clinical assessment, sonographic measurement of uterine length and estimated uterine weight were reviewed. Accuracy of these methods was ascertained by: 1) mean error, 2) mean standardized error, and 3) percentage of estimates within 10% of the actual weight. Among 210 hysterectomies, the mean (+/- standard deviation) of uterine weight was 514.9 gm +/- 647.0 gm (range 54-6700 gm) with 135 specimens (64.3%) being 500 gm and 75 > 500 gm. The receiver-operating curves for clinical assessment (0.82 +/- 0.03), uterine length (0.87 +/- 0.03) and Linear Regression Equation (0.82 +/- 0.04) are not significantly different (P > 0.05), having similar abilities to differentiate uterine weight. The clinical estimate of uterine weight is as accurate as ultrasound in determining a uterus weighing > 500 gm but all three methods poorly predict actual uterine weight.