[The importance of ultra-sound cephalometry for the prediction of the date of delivery--a contribution to the assessment of duration of pregnancy (author's transl)].

On the basis of some statistical data ultrasound cephalometry for the prediction of term is discussed. These data should be considered when providing socalled test-graphs. The usefulness of the author's own standard graph is examined. Prediction with the biparietal diameter is not much less exact than after the rule of Naegele. Accuracy of prediction can be much improved by using both methods together, starting from the averages of both.