[Ultrasonographic examinations of the true conjugate (author's transl)].

The sonographic examination of the true conjugate is described. The results are compared with intraoperative and radiologic measurements. There is a good correlation between these data. In a number of 39 cases the true conjugate was 12.1 cm (MV) intraoperatively and 11.9 cm (MV) echographically. With ultrasonographic measurements during the last month of 776 pregnancies a mean value of 12.0 (+/- 0.8 cm SD) was found. Based on these results one may conclude, that in correlation to the acceleration of the human body growth there is in this material also an increase of the true conjugate, which usually is quoted in the literature to be 11 cm.