Sonographic fetal weight estimation at the last weeks of third trimester in low-risk pregnancies is an effective method for diagnosis of fetal growth restriction (FGR) permitting close surveillance and timely delivery. The need for a systematic ultrasound evaluation at the last weeks of a low-risk pregnancy and the best time to perform it remains controversial. The most commonly used clinical screening tool in this population is the serial measurement of symphysis-fundus distance, which is a method of a variable and low sensitivity for detection of FGR.