A new sonographic approach to predict cephalo-pelvic disproportion: the HC/OC ratio

Many strategies have previously been implemented to prevent fetal overgrowth potentially resulting in obstructed labour. Rather than fetal size alone an overall assessment of the relation between the passage (pelvic inlet) and the passenger should be more helpful in predicting labour dystocia linked to cephalo-pelvic disproportion. The aim of this study is to evaluate the performance of the ratio between the sonographic measurement of fetal Head Circumference (HC) to the Obstetric Conjugate (OC) (HC/OC ratio) in the prediction of the mode of delivery.