Correlation of cephalopelvimetry to obstetrical outcome with special reference to radiologic disproportion.

It has been claimed that there is inadequate statistical correlation of pure pelvimetry with obstetrical outcome (7). Moreover, the incidence of cesarean section in a group of patients with more favorable pelvic measurements has been found to be higher than in a group in which these measurements were less favorable (6). This is in striking contrast to the results obtained with the cephalopeloimetric methods of Chassar Moir (8), Caldwell, Moloy, and Steer (9), and Ball (1, 2), which indicate a definite correlation between the measured cephalopelvic difference and obstetrical outcome. All three of these methods are deficient in that their accuracy is lowest where it is most needed—namely at the mid-pelvis—when disproportion exists. Moreover, the borderline group, in which no roentgen prediction is possible on the basis of these methods, is too large. Indeed, it exceeds the group in which a diagnosis of disproportion can be made with assurance. A preliminary study of the Ball method (12) was sufficiently pro...