Differentiation between normal and abnormal fetal growth

Establishing the standard for growth Accurate assessment of fetal growth status requires the definition of ‘normal’, i.e. the optimal growth of each baby. This includes the consideration of four factors which affect the standard: 1. Accurate dating is a first prerequisite for any growth standard. Ultrasound dating is much more accurate that menstrual dating. Because the distribution of menstrual dating error is positively skewed, many birth weight points at term appear at later gestations than they actually should be, leading to an artificial flattening of the growth curve and apparent increase in ‘post term ’ births [1]. In reality, growth in utero in normal pregnancy continues without diminished velocity until birth. Dating error can also severely affect the accuracy of gestation in the preterm gestation range. 2. The growth standard also needs to be individually adjusted for physiological factors known to affect birth weight and growth