ULTRASONIC FETAL WEIGHT ESTIMATION - ANALYSIS OF INTEROBSERVER AND INTRAOBSERVER VARIABILITY

Standard ultrasound measurements were performed by two observers in 40 third-trimester fetuses. Observers were blinded to the results of the meaurements. Estimated fetal weight (EFW) was calculated using two pu blished formulae. The intra-observer standard deviation for EFW, asses sed using one-way analysis of variance, was <75 g for both observers. The 95% prediction intervals for inter-observer comparisons of EFW, ca lculated using the limits of agreement method, were -187.3 g to 139.8 g, and -159.9 g to 124.3 g, using the two formulae. The results sugges t that measurements of EFW are reproducible. The prediction interval i s comparable to the weekly fetal weight increment in normal fetuses. ( C) 1993 John Wiley & Sons, Inc.