The descent of the fetal head is not modified by mobile epidural analgesia: a controlled sonographic study.

The aim of our study was to assess the sonographic indices of fetal head progression obtained by three-dimensional ultrasound during the second stage of labor in women with and without mobile epidural analgesia. Sonographic volume data sets were obtained with a transperineal approach every 20 min from the beginning of the active second stage until delivery. The ultrasound parameters were calculated off-line from each volume and compared between women with and without epidural analgesia. All the sonographic measurements of the fetal head descent were comparable at each time interval between the two groups. This observation suggests that mobile epidural analgesia is not likely to affect the dynamics of the second stage of labor.