Estimation of fetal weight by real-time sonography.

The accuracy of estimating fetal weight with real-time ultrasonography was studied in 81 fetuses. The technique is described and results are compared with those obtained by the B-scan technique. The absolute mean error was 228 g or 8.3% of the mean weight. Sixty percent of the measurements fell within 10% of the actual birth weight. The estimates were more accurate in the low (less than 1500 g) and in the high (more than 4000 g) weight groups. The easy access, simple technique, and reasonable accuracy of realtime scanners, as well as the development in progress for more reliable instruments, enable us to advocate its value for estimation of fetal weight in the delivery suite.