A preliminary evaluation of Cave's roentgenographic method of fetal cephalometry

A brief review of the literature relating to roentgenographic cephalometry has been presented. Particular emphasis has been given to the recent work of Cave, and his so-called precision method has been evaluated. If grossly unsatisfactory roentgenograms are excluded—and we are of the opinion that such roentgenograms can usually be excluded—accurate measurements of diameters of the fetal skull in the uterus to within ±6.6 per cent can be obtained by this method in approximately 85 per cent of the cases. In the case of measurements of fetal skulls adjudged to be of grade A in the roentgenogram, accuracy to within ±5.5 per cent was consistently obtained (92 per cent). We believe that a simple, inexpensive, and relatively precise technique of roentgenographic cephalometry might well represent a helpful adjunct in the management of suspected cephalopelvic disproportion in the primigravid woman for whom a trial of labor has been planned and a fetal development above the average is suspected. Although this method, in our limited experience, does not seem to be a method of precision, it is certainly deserving of further investigation.