Clinical validation of two equations in antenatal prediction of Chinese fetal weight by ultrasonography.

The purpose of this series is to prospectively validate the Chinese equations for predicting fetal weight developed in a previous study. A total of 640 Chinese fetuses were examined antenatally for biparietal diameter (BPD), abdominal circumference (AC) and femur length (FL) by real-time ultrasonography within two days of delivery. The results showed the actual birth weight (BW) to be highly correlated with the estimated body weight for both the equation using BPD and AC (EBW1) (r = 0.888, p less than 0.0001) and the equation using BPD, AC and FL (EBW2) (r = 0.890, p less than 0.0001). Our results demonstrate that the Chinese equations developed by Hsieh et al are a better fit for Chinese fetuses than the foreign equations are. Also, the two Chinese equations predict fetal weight well between 2,000 g and 4,000 g, but further modification is needed in cases where the BW is less than 2,000 g or greater than 4,000 g.