[Correcting occiput posterior position during labor: the role of maternal positions]

Occipito-posterior presentation represents 10 to 34% of cephalic presentations in early labor. Spontaneous rotation during labor to occipito-anterior mode occurs in most cases, but 5 to 8% of fetuses will persist in posterior position for the expulsive phase of delivery. Previous research has shown that this presentation carries an increased risk of unusually long labor, maternal and fetal exhaustion, instrument-assisted delivery, severe perineal injury, and cesarean section. The diagnosis of posterior variety is usually made quite late at the end of dilation. Several researchers have reported the benefits of determining presentation during labor by transabdominal ultrasonography. Some obstetrical techniques to correct these presentations at complete dilation have also been described. In the case of diagnosis of posterior variety, the usual attitude is expectant management. Postural techniques to promote physiological labor and delivery have been documented in the literature. De Gasquet has described a very precise technique to facilitate fetal rotation, but its effectiveness has never been assessed scientifically. A Cochrane review on the topic has shown that similar positions are well accepted by women and reduce back pain. On the other hand, the sample size of included studies appeared inadequate to assess their interest for use in childbirth, in general, and for adverse outcomes associated with posterior presentation varieties in particular. Attempts to correct the fetal malposition during the expansion phase would allow to reduce adverse outcomes during the expulsive phase of delivery. Further research is necessary to assess the efficacity of specific maternal positions during labor for the correction of fetal posterior presentation.