[Choice of ultrasound fetal weight estimation formulae]

Ultrasound estimation of fetal weight has been widely used in obstetrics practice and become an assistant diagnostic method for intrauterine growth retardation (IUGR) and large gestational age (LGA). To assess the accuracy of different fetal weight estimation formulae, 1300 fetuses with gestational age ranging from 28 to 40 weeks, whose mothers had no pregnant complications, were estimated by using four selected formulae (R2 > 95%). The results were compared with the average birth weight at the same gestational weeks in 15 cities of China. 188 fetuses were subjected to ultrasound examination one week before their birth. The estimated weights by different formulae were compared with their birth weights. 46 IUGR fetuses and 57 LGA fetuses, who were delivered in our hospital, were used to evaluate the diagnostic accuracy of the four fetal weight estimation formulae. The ideal formulae and the way to improve the accuracy of the fetal weight estimation were discussed.