[Clinical study of Osaka formula and improved multiparameter ultrasonic measurement for fetal weight estimation].
OBJECTIVE
To analyze the factors affecting the accuracy of Osaka formula multiparameter ultrasound-based fetal mass estimation, thereby establishing new formulas to improve the accuracy of the estimation.


METHODS
A retrospective review was conducted among 519 healthy women with singleton pregnancy. Three days before the delivery (between 37 and 42 weeks' gestation), ultrasonic measurement of the fetal weight and other indices of the fetus was routinely performed. Correlation and multiple linear stepwise regression analysis were used to correct the 3 equations, which, along with Osaka University formula, were used to predict another 219 fetuses' birth weight. The coincidence rate of the predicted value and with the actual birth weight, and the absolute error and relative error were compared between the equations.


RESULTS
The fetal abdominal area (AA) and abdominal circumference (AC) showed the most conspicuous influence on the estimated fetal birth weight, and fetal humerus length (HL) was more sensitive than femur length (FL) for the estimation. Three new regression equations were established, among which the equation 2 (fetal birth weight=1082.859+4.116xAAxHL) showed the best accuracy in clinical prediction.


CONCLUSIONS
AA,AC and HL are more sensitive indices for estimation of the fetal birth weight, and the equation 2 established in this study still awaits further verification for its clinical value.
Qiu
Yu-wen
YW
Department of Obstetrics and Gynecology, Nangfang Hospital, Southern Medical University, Guangzhou 510515, China. qyw7629@sina.com
Zhong
Mei
M
Chen
Cui-hua
CH
Hu
Mao-lan
ML
Chen
Lei-ning
LN
Sun
Xiu-yun
XY
Su
Gui-dong
GD
Song
Tian-rong
TR
Yu
Yan-hong
YH
D000005:Abdomen / Q000000981:diagnostic imaging; D000886:Anthropometry / Q000379:methods*; D005260:Female; D020567:Fetal Weight; D006801:Humans; D006811:Humerus / Q000000981:diagnostic imaging; D011247:Pregnancy; D012016:Reference Values; D012044:Regression Analysis; D012189:Retrospective Studies; D016216:Ultrasonography, Prenatal / Q000379:methods*