To estimate the fetal weight using ultrasonic measurements of the biparietal diameter (BPD), head circumference (HC), AC, and femur length (FL), investigators developed mathematical formulas and constricted percentile nomograms of estimation of fetal weight (EFW) at different gestational ages. The most commonly used equations and nomograms are those of Shepard et al, (1982)28, and Hadlock et al. (1985), and most ultrasound machines have incorporated into their software one or both of these nomograms. The majority of the literature defines FGR as all the fetuses with sonographic estimated weight below the 10th percentile for the gestational age. In addition to the 10th percentile, investigators have used the 5th, the 3rd, and the 2.5th percentiles of the EFW at a given gestational age to define FGR. The rationale behind this variation is that the lower the percentile, the higher the probability of selecting fetuses with pathological growth restriction. Cardiotocography is the most widely used surveillance measure for monitoring PGR pregnancies. A tracing with good variability provides strong reassurance of good fetal oxygenation. It is an important tool in the follow-up of PFGR fetus. When PFGR is detected in early stages, FHR monitoring will show a sequence of changes that correlate with worsening in the fetal situation. The usual order of appearance of FHR monitoring changes is lack of accelerations, decreased variability, and onset of spontaneous decelerations. All, some, or none of these abnormalities may be present in the initial evaluation of PFGR. They not only are dependent on the severity of the fetal compromise but also on the gestational age at the time of the fetal assessment.