The physician responsible for the labor will perform digital examinations (fetal station and position and cervical dilatation). Fetal station will be related to the ischial spine from -5 to +4 as described by WHO and illustrated in Figure 111. Another obstetrician or midwife blinded to the results from the clinical examination will perform the ultrasound measurements. The physician responsible for the labor will be blinded to the ultrasound measurements.