[Significance of various parameters of ultrasonic fetometry for the weight computation of the fetus].

In ultrasonic diagnostics, the fetal weight has been estimated on the basis of different dimensions of the fetal head or body either alone or in combination. When single dimensions have been used in late pregnancy, it has been possible to estimate the weight with an accuracy of 300--500 g, calculated as a standard deviation. When several dimensions are combined, the accuracy of the estimate is improved by 20--40%. The most commonly used dimensions are the biparietal diameter of the head and the thoracal or abdominal cross-section of the body. The ratio between the dimensions of the head and the body is also significant in diagnosing retardation of fetal growth. Although certain more complicated and time-consuming methods, such as the measurements of the volume of the fetal head and body, could yield somewhat more accurate estimates of fetal weight, they are not expedient in practical work. Scientific research is naturally a different matter.