BackgroundThe occipito-posterior (OP) fetal head position during the first stage of labour occurs in 10-34% of cephalic presentations. Most will spontaneous rotate in anterior position before delivery, but 5-8% of all births will persist in OP position for the third stage of labour. Previous observations have shown that this can lead to an increase of complications, such as an abnormally long labour, maternal and fetal exhaustion, instrumental delivery, severe perineal tears, and emergency caesarean section. Usual care in the case of diagnosis of OP position is an expectant management. However, maternal postural techniques have been reported to promote the anterior position of the fetal head for delivery. A Cochrane review reported that these maternal positions are well accepted by women and reduce back pain. However, the low sample size of included studies did not allow concluding on their efficacy on delivery outcomes, particularly those related to persistent OP position. Our objective is to evaluate the efficacy of maternal position in the management of OP position during the first stage of labour.Methods/designA randomised clinical trial is ongoing in the maternity unit of the Geneva University Hospitals, Geneva, Switzerland. The unit is the largest in Switzerland with 4,000 births/year. The trial will involve 438 women with a fetus in OP position, confirmed by sonography, during the first stage of the labour. The main outcome measure is the position of the fetal head, diagnosed by ultrasound one hour after randomisation.DiscussionIt is important to evaluate the efficacy of maternal position to correct fetal OP position during the first stage of the labour. Although these positions seem to be well accepted by women and appear easy to implement in the delivery room, the sample size of the last randomised clinical trial published in 2005 to evaluate this intervention had insufficient power to demonstrate clear evidence of effectiveness. If the technique demonstrates efficacy, it would reduce the physical and psychological consequences of complications at birth related to persistent OP position.Trial registrationClinicalTrials.gov, http://www.clinicaltrials.gov: (no. NCT01291355).